Plating apparatus and method

ABSTRACT

A plating apparatus continuously plates a surface of a substrate with metal and performs its supplementary process in one housing unit. The plating apparatus comprises a cassette stage for placing a substrate cassette thereon, a pre-treatment unit for pre-treating a surface of a substrate, and a plating unit for plating a surface of the substrate pre-treated in the pre-treatment unit. The plating apparatus further comprises a first substrate stage disposed between the cassette stage and the pre-treatment unit, a cleaning and drying unit disposed between the cassette stage and the first substrate stage, a first transfer device, and a second transfer device. The first transfer device transfers a substrate between the substrate cassette, the cleaning and drying unit, and the first substrate stage. The second transfer device transfers a substrate between the first substrate stage, the pre-treatment unit, and the plating unit.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a plating apparatus and method,and more particularly to a plating apparatus and method for fillinginterconnection grooves formed in a semiconductor substrate or the likewith metal such as copper.

[0003] 2. Description of the Related Art

[0004] Generally, aluminum or aluminum alloy has been surface of asemiconductor substrate. The higher integration of integrated circuitson the semiconductor substrate requires that a material having a higherelectric conductivity should be used for interconnection circuits.Therefore, there has been proposed a method comprising plating a surfaceof a substrate to fill interconnection patterns formed in the substratewith copper or copper alloy.

[0005] Various methods such as chemical vapor deposition (CVD) process,sputtering process, and the like have been used to fill interconnectionpatterns formed in a substrate with copper or copper alloy. However,when a metallic layer on a substrate is formed of copper or copperalloy, i.e., when copper interconnections are formed on the substrate,the CVD process requires high cost, and, if an aspect ratio is high(i.e., the depth of the pattern is larger than the width), then it isdifficult to fill the interconnection patterns with copper or copperalloy in the sputtering process. Therefore, the aforementioned platingmethod is most effective to fill interconnection patterns formed in asubstrate with copper or copper alloy.

[0006] There are various methods for plating a surface of asemiconductor substrate with copper. For example, in a cup-type platingmethod, a dip-type plating method, or the like, a plating containeralways holds a plating solution, and a substrate is dipped into the,plating solution. In another plating method, a plating container holds aplating solution only when a substrate is fed into the platingcontainer. Further, in an electrolytic plating method, an electricpotential difference is applied to plate a substrate. On the other hand,in an electroless plating method, an electric potential difference isnot applied.

[0007] A conventional plating apparatus for plating a substrate withcopper in these methods comprises a plating unit for plating asubstrate, and, in addition, a plurality of supplementary units such asa cleaning unit for cleaning and drying a plated substrate and atransfer robot horizontally disposed for transferring a substratebetween these units. The substrate is transferred between these units. Apredetermined process is performed in each of units, and then thesubstrate is transferred to a next unit.

[0008] However, with the conventional plating apparatus, since it isdifficult to efficiently dispose units for plating a substrate orperforming its supplementary process in one housing unit, theconventional plating apparatus requires a large space to be installed inorder to continuously plate the substrate in the housing unit. Further,for example, when the substrate is plated in a housing unit having aclean atmosphere, chemicals used in the plating process are diffused aschemical mist or gas and hence attached to a processed substrate.

SUMMARY OF THE INVENTION

[0009] The present invention has been made in view of the abovedrawbacks. It is therefore an object of the present invention to providea plating apparatus and method which comprises a plurality of units(pieces of equipment) disposed efficiently in one housing unit forcontinuously plating a substrate, and can hence reduce a space to beinstalled, and can prevent the substrate from being contaminated withchemicals used in the plating process.

[0010] According to a first aspect of the present invention, there isprovided a plating apparatus for continuously plating a surface of asubstrate with metal and performing its supplementary process in onehousing unit. The plating apparatus comprises a cassette stage forplacing a substrate cassette thereon, the substrate cassetteaccommodating a substrate, a pre-treatment unit for pre-treating asurface of a substrate and a plating unit for plating a surface of thesubstrate pre-treated in the pre-treatment unit. A first substrate stageis disposed between the cassette stage and the pre-treatment unit forholding a substrate placed thereon. A cleaning and drying unit isdisposed between the cassette stage and the first substrate stage forcleaning a plated substrate with pure water and drying the substrate. Afirst transfer device transfers a substrate between the substratecassette, the cleaning and drying unit, and the first substrate stage,and a second transfer device transfers a substrate between the firstsubstrate stage, the pre-treatment unit, and the plating unit.

[0011] With this construction, a substrate is pre-treated and platedafter being taken out of the substrate cassette, and then cleaned withpure water and dried. Thus, a series of the processes can be performedcontinuously and efficiently in one housing unit, and hence the platedsubstrate can successively be transferred to a next unit.

[0012] According to a second aspect of the present invention, there isprovided a plating apparatus for continuously plating a surface of asubstrate with metal and performing its supplementary process in onehousing unit. The plating apparatus comprises a cassette stage forplacing a substrate cassette thereon, the substrate cassetteaccommodating a substrate, a pre-treatment unit for pre-treating asurface of a substrate and a plating unit for plating a surface of thesubstrate pre-treated in the pre-treatment unit. A first substrate stageis disposed between the cassette stage and the pre-treatment unit forholding a substrate placed thereon and a chemical liquid cleaning unitdisposed between the cassette stage and the first substrate stage forcleaning a plated substrate with chemical liquid. A cleaning and dryingunit is disposed between the cassette stage and the chemical liquidcleaning unit for cleaning a plated substrate with pure water and dryingthe substrate; a second substrate stage is disposed between the chemicalliquid cleaning unit and the cleaning and drying unit for holding asubstrate placed thereon. A first transfer device transfers a substratebetween the substrate cassette, the cleaning and drying unit, and thesecond substrate stage, a second transfer device transfers a substratebetween the first substrate stage, the pre-treatment unit, and theplating unit, and a third transfer device transfers a substrate betweenthe first semiconductor stage, the chemical liquid cleaning unit, andthe second substrate stage.

[0013] With this construction, a substrate is pre-treated and platedafter being taken out of the substrate cassette, and then cleaned withchemical liquid. Thereafter, the substrate is cleaned with pure waterand dried. Thus, a series of the processes can be performed continuouslyand efficiently in one housing unit, and hence the plated substrate cansuccessively be transferred to a next unit.

[0014] In a preferred aspect of the present invention, at least one ofthe first substrate stage and the second substrate stage comprises twosubstrate stages, and at least one of the two substrate stages in the atleast one of the first substrate stage and the second substrate stage isconstituted so as to place a substrate thereon and clean the substrate.With this construction, at least one of a plated substrate and asubstrate cleaned with chemical liquid can be placed on and cleaned inthe substrate stage having a cleaning function, and can then betransferred to a next unit.

[0015] In a preferred aspect of the present invention, the housing unithas a partition wall for dividing the housing unit into a platingsection and a clean section. The plating section has the pre-treatmentunit, the plating unit, the fist substrate stage, and the secondtransfer device therein. The clean section has another unit therein. Thepartition wall has a shutter for passing a substrate therethrough; aircan individually be supplied into and exhausted from each of the platingsection and the clean section, and the pressure of the clean section iscontrolled so as to be higher than the pressure of the plating section.

[0016] In the plating section, chemicals used in the pre-treatment andplating processes are diffused as chemical mist or gas. With the aboveconstruction, the plating section is separated from the clean sectionrequired to be clean, and measures against particles are taken in eachof the sections. When the pressure of the clean section is controlled soas to be higher than the pressure of the plating section, the chemicalmist or gas can be prevented from being attached to a processedsubstrate.

[0017] In a preferred aspect of the present invention, a container foraccommodating a substrate for trial operation is disposed in the housingunit and one of the transfer devices takes out the substrate for trialoperation from the container and returns the substrate for trialoperation to the container. This construction can eliminatecontamination or lowering of the throughput caused by introduction ofthe substrate for trial operation from the outside when trial operationis conducted.

[0018] In a preferred aspect of the present invention, the container foraccommodating a substrate for trial operation is disposed in thevicinity of the first substrate stage. The second transfer device takesout the substrate for trial operation from the container and returns thesubstrate for trial operation to the container. With this construction,trial operation using a substrate for trial operation can be conductedin such a manner that the substrate for trial operation is pre-treated,plated, cleaned and dried, and then returned to the container.

[0019] A plurality of plating units may be provided in the housing, anda plating solution may respectively be fed to each of the plating unitsfrom a plating solution regulating tank in a single plating processsystem. In this case, when a plating solution regulating tank having alarge capacity is used in the process plating system, and the flow ratein each of the plating units is controlled, a variation in quality ofthe plating solution respectively fed to each of the plating units canbe suppressed.

[0020] According to a third aspect of the present invention, there isprovided a processing apparatus for processing a semiconductor substratewith chemical liquid or pure water, the processing apparatus comprisingan inverting mechanism for inverting a semiconductor substrate.

[0021] According to a fourth aspect of the present invention, there isprovided a plating apparatus for plating a surface of a semiconductorsubstrate. The plating apparatus comprises a pre-treatment unit forpre-treating a semiconductor substrate to be plated with chemical liquidor pure water, the pre-treatment unit having an inverting mechanism forinverting the semiconductor substrate, and a plating unit for plating asurface of the semiconductor substrate pre-treated in the pre-treatmentunit. With this construction, the surface of the substrate ispre-treated with chemical liquid in such a state that the front surfaceof the substrate faces upwardly. Thereafter, the substrate is invertedso that the front surface of the substrate faces downwardly, and thentransferred to the plating unit, in which the substrate can be plated bya face-down-type plating.

[0022] According to a fifth aspect of the present invention, there isprovided a plating method for continuously plating a surface of asubstrate with metal and performing its supplementary process in onehousing unit. The plating method comprises placing a substrate cassetteaccommodating a substrate on a cassette stage, transferring thesubstrate in the substrate cassette to a first substrate stage by afirst transfer device, transferring the substrate on the first substratestage to a pre-treatment unit from the first substrate stage by a secondtransfer device, transferring the substrate pre-treated in thepre-treatment unit to a plating unit by the second transfer device, andtransferring the substrate plated in the plating unit to a cleaning anddrying unit.

[0023] According to a sixth aspect of the present invention, there isprovided a plating method for continuously plating a surface of asubstrate with metal and performing its supplementary process in onehousing unit, The plating method comprises placing a substrate cassetteaccommodating a substrate on a cassette stage, transferring a substratein the substrate cassette to a first substrate stage by a first transferdevice, transferring the substrate on the first substrate stage to apre-treatment unit from the first substrate stage by a second transferdevice, transferring the substrate pre-treated in the pre-treatment unitto a plating unit by the second transfer device, transferring thesubstrate plated in the plating unit to the first substrate stage by thesecond transfer device, transferring the substrate on the firstsubstrate stage to a chemical liquid cleaning unit from the firstsubstrate stage by a third transfer device, transferring the substratecleaned with chemical liquid in the chemical liquid cleaning unit to thesecond substrate stage, and transferring the substrate on the secondsubstrate stage to a cleaning and drying unit from the second substratestage.

[0024] According to a seventh aspect of the present invention, there isprovided a plating unit having a plating process container, the platingprocess container comprises a plating container having a plating chambertherein for holding a plating solution in the plating chamber, theplating chamber having an anode at its bottom. A plurality of platingsolution supply nozzles eject the plating solution toward the centralportion of the plating chamber. A regulating ring is provided in thevicinity of the peripheral portion of the plating chamber. A firstplating solution discharge port discharges the plating solution in theplating chamber from the bottom of the plating chamber and a secondplating solution discharge port discharges the plating solutionoverflowing the peripheral portion of the plating chamber.

[0025] With this construction, the plating solution ejected from theplating solution supply nozzles into the central portion of the platingchamber collides at the central portion of the plating chamber to forman upward flow and a downward flow. The upward flow pushes up the liquidsurface of the plating solution, and the downward flow pushes awaypeeled pieces of a black film formed on the surface of the anode. Thus,air bubbles can be prevented from remaining between the substrate andthe liquid surface of the plating solution, and the black film cansimultaneously be prevented from being attached to the surface of thesubstrate.

[0026] In a preferred aspect of the present invention, the anode is heldby an anode support detachably mounted on the plating container. In thiscase, the anode can easily be attached to and detached from the platingcontainer via the anode support to thus facilitate maintenance andreplacement of the anode, and the like.

[0027] A labyrinth seal comprising a plurality of grooves arranged inparallel may be provided on at least one of the anode support and theplating container around the inlet of the anode support. Such alabyrinth seal can ensure reliable sealing of a gap between the platingcontainer and the anode support to thus prevent the plating solutionfrom leaking out.

[0028] An inert gas introduction passage for introducing inert gas and aplating solution return passage for discharging the plating solutionremaining within the grooves may be connected to at least one of thegrooves. When the plating solution remains within the groovesconstituting the labyrinth seal, an inert gas is introduced to thegrooves through the inert gas introduction passage, and hence theplating solution remaining within the grooves can be discharged to theexterior through the plating solution return passage.

[0029] According to an eighth aspect of the present invention, there isprovided a plating unit comprising a rotatable housing having asubstrate holding member provided at the lower end thereof, thesubstrate holding member projecting radially inwardly and abutting aperipheral portion of a substrate to hold the substrate. A pressingmember is disposed in the housing for pressing the peripheral portion ofthe substrate against the substrate holding member to hold thesubstrate, the pressing member being rotatable together with thehousing.

[0030] With this construction, a substrate can be transferred to thepressing member from a robot arm or the like in such a state that thepressing member is raised, and then the pressing member can be lowered.The peripheral portion of the substrate is held between the pressingmember and the substrate holding member of the housing, and hence thesubstrate can be raised to be rotated in this state.

[0031] In a preferred aspect of the present invention, a plurality ofair vent holes are formed in the substrate holding member provided atthe lower end of the housing. In this case, air bubbles between thesubstrate and the liquid surface of the plating solution can easily bedischarge through the air vent holes to the exterior.

[0032] In a preferred aspect of the present invention, the pressingmember comprises a chuck mechanism disposed at the peripheral portionthereof for detachably holding the substrate on the lower surface of thepressing member.

[0033] In a preferred aspect of the present invention, a contact for acathode electrode is disposed on the substrate holding member of thehousing and a feeding contact is disposed at the outer circumferentialside of the pressing member. The contact for the cathode electrode isenergized when a substrate is held by the substrate holding member andthe pressing member. The feeding contact energizes the contact for thecathode electrode when the pressing member is lowered to bring thecontact for the cathode electrode into contact with the feeding contact.In this case, since the plating solution is reliably sealed by thesubstrate holding member, the plating solution can be prevented frombeing brought into contact with the contact for the cathode electrodeand the feeding contact.

[0034] According to a ninth aspect of the present invention, there isprovided a plating unit comprising a head having a rotatable housing, avertically movable pressing member housed in the housing and a substrateholding member disposed in the housing for holding a peripheral portionof a substrate between the pressing member ring and the substrateholding member. A plating process container is disposed below the headfor holding a plating solution so that the liquid surface of the platingsolution has a liquid level for plating which is higher than a positionof a substrate held by the housing, and a liquid level for transferringthe substrate which is lower than a position of a substrate held by thehousing.

[0035] According to a tenth aspect of the present invention, there isprovided a plating unit comprising a head having a rotatable housing avertically movable pressing ring housed in the housing and a substrateholding member disposed in the housing for holding a peripheral portionof a substrate between the pressing ring and the substrate holdingmember. A plating process container is disposed below the head forholding a plating solution so that the liquid surface of the platingsolution has a liquid level for plating which is higher than a positionof a substrate held by the housing, and a liquid level for transferringthe substrate which is lower than a position of a substrate held by thehousing.

[0036] According to an eleventh aspect of the present invention, thereis provided a plating unit comprising a head having a rotatable housing,a clamp mechanism with a swing link housed in the housing, the swinglink being swingable in the horizontal direction, and a substrateholding member disposed in the housing for holding a peripheral portionof a substrate between the swing link and the substrate holding member.A plating process container is disposed below the head for holding aplating solution so that the liquid surface of the plating solution hasa liquid level for plating which is higher than a position of asubstrate held by the housing, and a liquid level for transferring thesubstrate which is lower than a position of a substrate held by thehousing.

[0037] According to a twelfth aspect of the present invention, there isprovided a plating unit comprising a head having a rotatable housing,the housing having an elastic member therein elastically deformable bypneumatic pressure and a substrate holding member disposed in thehousing for holding a peripheral portion of a substrate between theelastic member and the substrate holding member; and a plating processcontainer is disposed below the head for holding a plating solution sothat the liquid surface of the plating solution has a liquid level forplating which is higher than a position of a substrate held by thehousing, and a liquid level for transferring the substrate which islower than a position of a substrate held by the housing.

[0038] According to a thirteenth aspect of the present invention, thereis provided a plating unit comprising a head having a rotatable housing,the housing having a substrate holding member for holding a substrate,and a plating process container disposed below the head for holding aplating solution so that the liquid surface of the plating solution hasat least two levels.

[0039] With this construction, the mechanism of the head can besimplified and compact. In addition, the plating process is carried outwhen the plating solution within the plating process container is at aliquid level for plating, while the substrate is dewatered andtransferred when the plating solution is at a liquid level fortransferring the substrate.

[0040] A contact for a cathode which is energized to the substrate whenthe substrate is held by the substrate holding member may be provided onthe upper surface of the substrate holding member of the housing.

[0041] A substrate centering mechanism for performing centering of asubstrate may be provided on the inner circumferential surface of thehousing above the substrate holding member. A substrate is held by atransfer robot or the like, is carried into the housing, and is placedon the substrate holding member. In this case, when holding of thesubstrate by the transfer robot or the like is released, the centeringof the substrate can be carried out.

[0042] The substrate centering mechanism may comprise a positioningblock having a tapered inner surface which is widened outwardly in theupward direction, an elastic member for inwardly urging the positioningblock, and a stopper for restricting inward movement of the positioningblock. While a substrate is guided by the tapered surface, the substrateis urged inwardly by the elastic member, thereby carrying out thecentering of the substrate. With this construction, a substrate is heldby a transfer robot or the like, is carried into the housing, and isplaced on the substrate holding member. In this case, when the center ofthe substrate deviates from the center of the substrate holding member,the positioning block is rotated outwardly against the urging force ofthe elastic member and, upon the release of holding of the substrate bythe transfer robot or the like, the positioning block is returned to theoriginal position by the urging force of the elastic member. Thus, thecentering of the substrate can be carried out.

[0043] According to a fourteenth aspect of the present invention, thereis provided a plating unit comprising a head having a substrate holdingmember for holding a substrate, a plating process container disposedbelow the head for holding a plating solution and a plating solutionsuction mechanism for removing plating solution remaining at a portionabutting the peripheral portion of a substrate at the innercircumferential end of the substrate holding member.

[0044] The plating solution is likely to be left at a portion abuttingthe peripheral portion of a substrate at the inner circumferential endof the substrate holding member. With this construction, the platingsolution remaining at the abutting portion is forced to be removed,thereby preventing the plating solution from being dried and becoming asource for particles.

[0045] A plating solution suction nozzle constituting the platingsolution suction mechanism may extend in an arc form along the innercircumferential surface of the substrate holding member and bevertically and horizontally movable. With this construction, the platingsolution left in the tip end of the annular projecting portion of thesubstrate holding member can be sucked and removed in a short time withhigh efficiency.

[0046] According to a fifteenth aspect of the present invention, thereis provided a plating apparatus for continuously plating a surface of asubstrate with metal and performing its supplementary process in onehousing unit. The plating apparatus comprises a cassette stage forplacing a substrate cassette thereon, the substrate cassetteaccommodating a substrate, a pre-plating unit for pre-plating a surfaceof a substrate and a plating unit for plating a surface of the substratepre-plated in the pre-plating unit. A first substrate stage is disposedbetween the cassette stage and the pre-plating unit for holding asubstrate placed thereon. A cleaning and drying unit is disposed betweenthe cassette stage and the first substrate stage for cleaning a platedsubstrate with pure water and then drying the substrate. A firsttransfer device transfers a substrate between the substrate cassette,the cleaning and drying unit, and the first substrate stage and a secondtransfer device transfers a substrate between the first substrate stage,the pre-plating unit, and the plating unit.

[0047] With this construction, a substrate is pre-plated and platedafter being taken out of the substrate cassette, and then cleaned withpure water and dried. Thus, a series of the processes can be performedcontinuously and efficiently in one housing unit, and hence the platedsubstrate can successively be transferred to a next unit.

[0048] According to a sixteenth aspect of the present invention, thereis provided a plating apparatus for continuously plating a surface of asubstrate with metal and performing its supplementary process in onehousing unit. The plating apparatus comprises a cassette stage forplacing a substrate cassette thereon, the substrate cassetteaccommodating a substrate, a pre-plating unit for pre-plating a surfaceof a substrate, and a plating unit for plating a surface of thesubstrate pre-plated in the pre-plating unit. A first substrate stage isdisposed between the cassette stage and the pre-plating unit for holdinga substrate placed thereon. A chemical liquid cleaning unit is disposedbetween the cassette stage and the first substrate stage for cleaning aplated substrate with chemical liquid. A cleaning and drying unit isdisposed between the cassette stage and the chemical liquid cleaningunit for cleaning a plated substrate with pure water and then drying thesubstrate. A second substrate stage is disposed between the chemicalliquid cleaning unit and the cleaning and drying unit for holding asubstrate placed thereon. A first transfer device transfers a substratebetween the substrate cassette, the cleaning and drying unit, and thesecond substrate stage, a second transfer device transfers a substratebetween the first substrate stage, the pre-plating unit, and the platingunit, and a third transfer device transfers a substrate between thefirst semiconductor stage, the chemical liquid cleaning unit, and thesecond substrate stage.

[0049] With this construction, a substrate is pre-plated and platedafter being taken out of the substrate cassette, and then cleaned withchemical liquid. Thereafter, the substrate is cleaned with pure waterand dried. Thus, a series of the processes can be performed continuouslyand efficiently in one housing unit, and hence the plated substrate cansuccessively be transferred to a next unit.

[0050] According to a seventeenth aspect of the present invention, thereis provided a plating apparatus for continuously plating a surface of asubstrate with metal and performing its supplementary process in onehousing unit. The plating apparatus comprises a cassette stage forplacing a substrate cassette thereon, the substrate cassetteaccommodating a substrate, a pre-treatment unit for pre-treating asurface of a substrate and a plating unit for plating a surface of thesubstrate pre-treated in the pre-treatment unit. A first substrate stageholds a substrate placed thereon. A cleaning and drying unit cleans aplated substrate with pure water and dries the substrate. A firsttransfer device transfers a substrate and a second transfer devicetransfers a substrate. The housing unit has a partition wall fordividing the housing unit into a plating section and a clean section.The plating section has at least the pre-treatment unit, the platingunit, the fist substrate stage, and the second transfer device therein.The clean section has another unit therein, and the pressure of theclean section is controlled so as to be higher than the pressure of theplating section.

[0051] In a preferred aspect of the present invention, the firstsubstrate stage comprises two substrate stages, and at least one of thetwo substrate stages in the first substrate stage is constituted so asto place a substrate thereon and clean a substrate.

[0052] In a preferred aspect of the present invention, a container foraccommodating a substrate for trial operation is disposed in the housingunit, and one of the transfer devices takes out the substrate for trialoperation from the container and returns the substrate for trialoperation to the container.

[0053] The above and other objects, features, and advantages of thepresent invention will be apparent from the following description whentaken in conjunction with the accompanying drawings which illustratepreferred embodiments of the present invention by way of example.

BRIEF DESCRIPTION OF THE DRAWINGS

[0054]FIGS. 1A through 1C are cross-sectional views showing an exampleof a plating process utilizing the plating apparatus according to thepresent invention;

[0055]FIG. 2 is a plan view showing a layout of a plating apparatusaccording to a first embodiment of the present invention;

[0056]FIG. 3 is an explanatory view showing an air current in theplating apparatus shown in FIG. 2;

[0057]FIG. 4 is an enlarged cross-sectional view showing a main part ofa plating unit in the plating apparatus according to the firstembodiment of the present invention;

[0058]FIG. 5 is an enlarged view showing a part of the plating unitshown in FIG. 4;

[0059]FIG. 6 is a plan view showing a plating process container;

[0060]FIG. 7 is a plan view showing an arrangement of contacts forcathode electrodes;

[0061]FIG. 8 is a plan view showing a head in the plating unit;

[0062]FIG. 9 is a front view of the head shown in FIG. 8;

[0063]FIG. 10 is a front view explanatory of the rotation of the head inthe plating unit;

[0064]FIG. 11 is a front view explanatory of the raising and lowering ofthe head in the plating unit;

[0065]FIG. 12 is a front view explanatory of the raising and lowering ofa chuck mechanism in the head of the plating unit;

[0066]FIG. 13 is an enlarged cross-sectional view showing a part of thechuck mechanism shown in FIG. 12;

[0067]FIG. 14 is a plan view showing an inverter in the platingapparatus;

[0068]FIG. 15 is a front view showing the inverter shown in FIG. 14;

[0069]FIG. 16 is a cross-sectional view schematically showing a platingunit in a plating apparatus according to a second embodiment of thepresent invention;

[0070]FIG. 17 is a cross-sectional view schematically showing a platingunit in a plating apparatus according to a third embodiment of thepresent invention;

[0071]FIG. 18 is a cross-sectional view schematically showing a platingunit in a plating apparatus according to a fourth embodiment of thepresent invention;

[0072]FIG. 19 is a cross-sectional view schematically showing a platingunit in a plating apparatus according to a fifth embodiment of thepresent invention;

[0073]FIG. 20 is a cross-sectional view schematically showing a platingunit in a plating apparatus according to a sixth embodiment of thepresent invention;

[0074]FIG. 21 is a cross-sectional view showing a whole structure of aplating unit at the time of plating process in a plating apparatusaccording to a seventh embodiment of the present invention;

[0075]FIG. 22 is a schematic diagram showing a flow of a platingsolution in a plating apparatus provided with a plurality of the platingunits shown in FIG. 21;

[0076]FIG. 23 is a cross-sectional view showing a whole structure of theplating unit during a non-plating process (at the time of transfer of asubstrate);

[0077]FIG. 24 is a cross-sectional view showing a whole structure of theplating unit during maintenance;

[0078]FIG. 25 is a cross-sectional view explanatory of a relationshipamong a housing, a pressure ring, and a substrate during transfer of asubstrate;

[0079]FIG. 26 is an enlarged view showing a part of FIG. 25;

[0080]FIG. 27 is a schematic view explanatory of the flow of a platingsolution at the time of a plating process and at the time of anon-plating process;

[0081]FIG. 28 is an enlarged cross-sectional view showing a centeringmechanism in the plating unit;

[0082]FIG. 29 is a cross-sectional view showing a feeding contact(probe) in the plating unit;

[0083]FIG. 30 is a plan view showing a plating solution suctionmechanism in the plating unit; and

[0084]FIG. 31 is a front view showing the plating solution suctionmechanism.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0085] A plating apparatus according to embodiments of the presentinvention will be described below with reference to the accompanyingdrawings.

[0086] A plating apparatus according to embodiments of the presentinvention is used for plating a surface of a semiconductor substratewith copper, for thereby manufacturing semiconductor devices on whichinterconnections having a copper layer are formed. This plating processwill be described below with reference to FIGS. 1A through 1C.

[0087] As shown in FIG. 1A, an insulating film 2 of SiO₂ is depositedover an electrically conductive layer 1 a on a semiconductor base 1having semiconductor elements, and then a contact hole 3 and aninterconnection groove 4 are formed by lithography etching technology. Abarrier layer 5 made of TiN or the like is formed on the insulating film2, and a copper seed layer 7 used as a feeding layer in electrolyticplating is formed on the barrier layer 5 by sputtering or the like.

[0088] Subsequently, as shown in FIG. 1B, a surface of a substrate W isplated with copper. Hence, the contact hole 3 and the interconnectiongroove 4 on the semiconductor base 1 are filled with copper, and acopper layer 6 is formed on the insulating film 2. Thereafter, thecopper layer 6 on the insulating film 2 is removed by chemicalmechanical polishing (CMP) so that the surface of the copper layer 6filled in the contact hole 3 and the interconnection groove 4 is madesubstantially even with the surface of the insulating film 2. Thus, asshown in FIG. 1C, an interconnection comprising the copper layer 6 isformed.

[0089] A plating apparatus for electrolytically plating a semiconductorsubstrate W according to a first embodiment of the present inventionwill be described below with reference to FIG. 2. As shown in FIG. 2,the plating apparatus is disposed in a rectangular housing unit 10, andis constituted so as to plate a semiconductor substrate with coppercontinuously. The housing unit 10 has a partition wall 11 for dividingthe housing unit 10 into a plating section 12 and a clean section 13.Air can individually be supplied into and exhausted from each of theplating section 12 and the clean section 13. The partition wall 11 has ashutter (not shown) capable of opening and closing. The pressure of theclean section 13 is lower than the atmospheric pressure and higher thanthe pressure of the plating section 12. This can prevent the air in theclean section 13 from flowing out of the housing unit 10 and can preventthe air in the plating section 12 from flowing into the clean section13.

[0090] In the clean section 13, there are provided two cassette stages15 for placing a substrate cassette thereon, and two cleaning and dryingunits 16 for cleaning (rinsing) a plated substrate with pure water anddrying. Further, a rotatable fixed-type first transfer device (tetraxialrobot) 17 for transferring a substrate is provided in the clean section13. For example, the cleaning and drying unit 16 has cleaning liquidsupply nozzles for supplying ultrapure water to both surfaces of asubstrate, and spins the substrate at a high speed to dewater and drythe substrate.

[0091] On the other hand, in the plating section 12, there are providedtwo pre-treatment units 21 for pre-treating a surface of a substrate forplating, and inverting the pre-treated substrate with an inverter 20(see FIGS. 14 and 15), four plating units 22 for plating a surface of asubstrate with copper in such a state that the front surface of thesubstrate faces downwardly, and two first substrate stages 23 a, 23 bfor holding a substrate placed thereon. Further, a rotatable mobile-typesecond transfer device (tetraxial robot) 24 for transferring a substrateis provided in the plating section 12.

[0092] In the clean section 13, there are provided two chemical liquidcleaning units 25 for cleaning a plated substrate with chemical liquid,and second substrate stages 26 a, 26 b disposed between the chemicalliquid cleaning units 25 and the cleaning and drying units 16. Arotatable fixed-type third transfer device (tetraxial robot) 27 fortransferring a substrate is provided between the two chemical liquidcleaning units 25.

[0093] One of the first substrate stages and one of the second substratestages, i.e., the first substrate stage 23 b and the second substratestage 26 b, are constituted so as to clean the substrate with water.Each of the first substrate stage 23 b and the second substrate stage 26b has an inverter 20 for inverting a substrate (see FIGS. 14 and 15).

[0094] Thus, the first transfer device 17 transfers a substrate betweenthe substrate cassettes placed on the cassette stages 15, the cleaningand drying units 16, and the second substrate stages 26 a, 26 b. Thesecond transfer device 24 transfers a substrate between the firstsubstrate stages 23 a, 23 b, the pre-treatment units 21, and the platingunits 22. The third transfer device 27 transfers a substrate between thefirst substrate stages 23 a, 23 b, the chemical liquid cleaning units25, and the second substrate stages 26 a, 26 b.

[0095] A container 28 for accommodating substrates for trial operationis disposed in the housing unit 10, and located below the firstsubstrate stage 23 a. The second transfer device 24 takes out asubstrate for trial operation from the container 28, and returns it tothe container 28 after trial operation. Thus, the container 28 providedin the housing unit 10 for accommodating the substrates for trialoperation can eliminate contamination or lowering of the throughputcaused by introduction of substrates for trial operation from theoutside when trial operation is conducted.

[0096] As long as the substrates for trial operation can be taken outfrom the container 28 and returned to the container 28 by any of thetransfer devices, the container 28 may be placed anywhere in the housingunit 10. However, when the container 28 is disposed in the vicinity ofthe first substrate stage 23 a, the trial operation can be conducted insuch a manner that a substrate for trial operation is pre-treated,plated, cleaned and dried, and then returned to the container 28.

[0097] The transfer device 17 has two recess-type hands, respectivelyfor supporting a peripheral edge of a substrate by a recess. The upperhand is used for handling a dry substrate and the lower hand is used forhandling a wet substrate. Each of the transfer devices 24 and 27 has tworecess-type hands, which are used for handling a wet substrate. Thehands of the transfer devices are not limited to those types describedabove.

[0098] In the present embodiment, the plating apparatus comprises thechemical liquid cleaning units 25 for cleaning a surface of a substratewith chemical liquid such as dilute hydrofluoric acid or hydrogenperoxide. If it is not necessary to clean a plated substrate withchemical liquid, the chemical liquid cleaning units 25 are not required.In this case, the first transfer device 17 transfers a substrate betweenthe substrate cassettes placed on the cassette stages 15, the cleaningand drying units 16, and the first substrate stages 23 a, 23 b to thusdispense with the third transfer device 27 and the second substratestages 26 a, 26 b.

[0099] Next, the processing flow of the substrate in the platingapparatus according to the present embodiment will be described below.

[0100] The substrates are accommodated by the substrate cassette in sucha state that the front surface of the substrate (surface on whichsemiconductor elements are formed, i.e., surface to be processed) facesupwardly, and the substrate cassette accommodating such substrates isplaced on the cassette stage 15. The first transfer device 17 takes outa substrate from the substrate cassette, moves to the second substratestage 26 a, and places the substrate on the second substrate stage 26 a.Then, the third transfer device 27 transfers the substrate from thesecond substrate stage 26 a to the first substrate stage 23 a.Thereafter, the second transfer device 24 receives the substrate fromthe first substrate stage 23 a and transfers the substrate to thepre-treatment unit 21. After the pre-treatment of the substrate iscompleted in the pre-treatment unit 21, the substrate is inverted by theinverter 20 so that the front surface of the substrate faces downwardly,and then transferred to the second transfer device 24. The secondtransfer device 24 transfers the substrate to a head of the plating unit22.

[0101] After the substrate is plated and liquid on the substrate isremoved in the plating unit 22, the substrate is received by the secondtransfer device 24, which transfers the substrate to the first substratestage 23 b. The substrate is inverted by the inverter 20 provided at thefirst substrate stage 23 b so that the front surface faces upwardly, andthen transferred to the chemical liquid cleaning unit 25 by the thirdtransfer device 27. In the chemical liquid cleaning unit 25, thesubstrate is cleaned with chemical liquid and rinsed with pure water,and then the liquid on the substrate is removed by spinning. Thereafter,the substrate is transferred to the second substrate stage 26 b by thethird transfer device 27. Next, the first transfer device 17 receivesthe substrate from the second substrate stage 26 b, and transfers thesubstrate to the cleaning and drying unit 16. In the cleaning and dryingunit 16, the substrate is rinsed with pure water such as deionized waterand then spin-dried. The dried substrate is returned to the substratecassette placed on the cassette stage 15 by the first transfer device17.

[0102]FIG. 3 is a schematic view showing an air current in the housingunit 10. In the clean section 13, fresh external air is introducedthrough a pipe 30 and pushed into the clean section 13 through ahigh-performance filter 31 by a fan. Hence, downflow clean air issupplied from a ceiling 32 a to positions around the cleaning and dryingunits 16 and the chemical liquid cleaning units 25. A large part of thesupplied clean air is returned from a floor 32 b through a circulationpipe 33 to the ceiling 32 a, and pushed again into the clean section 13through the high-performance filter 31 by the fan, to thus circulate inthe clean section 13. A part of the air is discharged from the cleaningand drying units 16 and the chemical liquid units 25 through a pipe 34to the exterior, so that the pressure of the clean section 13 is set tobe lower than the atmospheric pressure.

[0103] The plating section 12 having the pre-treatment units 21 and theplating units 22 therein is not a clean section (but a contaminationzone). However, it is not acceptable to attach particles to the surfaceof the substrate. Therefore, in the plating section 12, fresh externalair is introduced through a pipe 35, and downflow clean air is pushedinto the plating section 12 through a high-performance filter 36 by afan, for thereby preventing particles from being attached to the surfaceof the substrate. However, if the whole flow rate of the downflow cleanair is supplied by only an external air supply and exhaust, then anenormous air supply and exhaust are required. Therefore, the air isdischarged through a pipe 38 to the exterior, and a large part of thedownflow is supplied by a circulating air through a circulation pipe 39extended from a floor 37 b, and in a state such that the pressure of theplating section 12 is maintained lower than the pressure of the cleansection 13.

[0104] Thus, the air returned to a ceiling 37 a through the circulationpipe 39 is pushed again into the plating section 12 through thehigh-performance filter 36 by the fan. Hence clean air is supplied intothe plating section 12 to thus circulate in the plating section 12. Inthis case, air containing chemical mist or gas emitted from thepre-treatment units 21, the plating units 22, the second transfer device24, and a plating solution regulating tank 40 is discharged through thepipe 38 to the exterior. Thus, the pressure of the plating section 12 iscontrolled so as to be lower than the pressure of the clean section 13.

[0105]FIG. 4 shows a main part of the plating unit 22. The plating unit22 mainly comprises a plating process container 46 in substantiallycylindrical form for holding a plating solution therein, and a head 47disposed above the plating process container 46 for holding a substrate.In FIG. 4, the head 47 is located in a plating position in which asubstrate W held by the head 47 is lowered.

[0106] The plating process container 46 comprises a plating chamber 49,which is upwardly opened, and a plating container 50 for holding aplating solution in the plating chamber 49. An anode 48 made ofresidual-phosphorus copper, for example, is provided at the bottom ofthe plating chamber 49. The anode is held by an anode support 52, whichis detachably mounted on the plating container 50, i.e., which isdrawably mounted via a knob 51 provided on the anode support 52. Theanode 48 is connected to an anode of a power supply for plating providedin an external control unit. A sealing member 200 for preventing theplating solution from leaking is interposed between the front surface ofthe plating container 50 and the backside surface of a flange 52 a inthe anode support 52. Thus, the anode 48 is held by the anode support 52detachably mounted on the plating container 50, causing the anode 48 tobe easily attached to and detached from the plating container 50 via theanode support 52. Accordingly, this construction facilitates maintenanceand replacement of the anode 48, and the like.

[0107] The anode 48 is made of copper containing 0.03% to 0.05%phosphorus (residual-phosphorus copper), and hence a black film isformed on the upper surface of the anode 48 as plating proceeds. Such ablack film can reduce generation of anode slime.

[0108] Plating solution supply nozzles 53 horizontally projecting towardthe center of the plating chamber 49 are provided on the innercircumferential wall of the plating container 50 at equal intervalsalong the circumferential direction. Each of the plating solution supplynozzles 53 is communicated with a plating solution supply passage 54extended vertically through the interior of the plating container 50. Inthe present embodiment, as shown in FIG. 6, four circumferentiallydivided plating solution reservoirs 202 in an arc-shaped form areprovided in the inner circumferential wall of the plating container 50.Each of the plating solution reservoirs 202 is communicated with theplating solution supply passage 54 located at the central portion alongthe circumferential direction of the plating solution reservoir 202.Each of the plating solution reservoirs 202 comprises two platingsolution supply nozzles 53 provided on both ends of the plating solutionreservoir 202. The plating solution of the same flow rate isrespectively supplied to each of the plating solution reservoirs 202 viacontrol valves 56 described later. Therefore, the plating solution ishomogeneously ejected from each of the plating solution supply nozzles53 into the plating chamber 49.

[0109] Each of the plating solution supply passages 54 is connected to aplating solution regulating tank 40 (see FIGS. 3 and 22) via a platingsolution supply pipe 55. Control valves 56 for controlling the backpressure to be constant are disposed on each of the plating solutionsupply pipes 55.

[0110] Further, the plating container 50 is provided with first platingsolution discharge ports 57 for withdrawing the plating solution 45 inthe plating chamber 49 from the peripheral portion of the bottom of theplating chamber 49, and second plating solution discharge ports 59 fordischarging the plating solution 45 overflowing a weir member 58provided at the upper end of the plating container 50. Each of the firstplating solution discharge ports 57 is connected to a reservoir 226 (seeFIG. 22) via a plating solution discharge pipe 60 a. A flow controller61 a is disposed on the plating solution discharge pipe 60 a. On theother hand, each of the second plating solution discharge ports 59 isconnected to the reservoir 226 via a plating solution discharge pipe 60b. A flow controller 61 b is disposed on the plating solution dischargepipe 60 b. The flow controller 61 b may not be provided, as shown inFIG. 22. The plating solution fed into the reservoir 226 is supplied tothe plating solution regulating tank 40 (see FIG. 3) from the reservoir226 by a pump 228. In the plating solution regulating tank 40, thetemperature of the plating solution is adjusted, and the concentrationof various components in the plating solution is measured and adjusted.Thereafter, the plating solution is supplied to the plating units (seeFIG. 22).

[0111] As shown in FIG. 6, a plurality of the first plating solutiondischarge ports 57 (16 ports in FIG. 6), which are in circular formhaving a diameter of 16 mm to 20 mm, for example, are disposed at equalintervals along the circumferential direction. A plurality of the secondplating solution discharge ports (3 ports in FIG. 6) 59 are inarc-shaped form having a central angle of about 25°.

[0112] The plating solution 45 ejected from the plating solution supplynozzles 53 is discharged to the reservoir 226 (see FIG. 22) from one orboth of the first plating solution discharge ports 57 and the secondliquid discharge ports 59, thereby keeping the liquid level of theplating solution 45 in the plating chamber 49 at a constant value.

[0113] As shown in FIG. 6, a lateral hole 204 extended in the horizontaldirection is provided at a predetermined position along the verticaldirection in the vicinity of the bottom of the plating chamber 49. Aliquid level sensor 206 is provided in the side wall of the platingchamber 49. The liquid level sensor 206 has a front end (lower end)reaching the lateral hole 204 and detects whether the liquid level ofthe plating solution is lower than the position of the lateral hole 204or not. For example, the front end of the liquid level sensor 206 isformed of Teflon, and, when the front end of the liquid level sensor 206is in the air, the difference in refractive index between Teflon and airis so large that a beam of light is returned to an original position(photodetector) due to total reflection. On the other hand, when thefront end of the liquid level sensor 206 is dipped in the platingsolution, the difference in refractive index between Teflon and theplating solution is so small that the beam of light is almost radiatedinto the plating solution and is not returned to the original position(photodetector) The liquid level sensor 206 utilizes such properties,for example, and hence detects the presence of the plating solution inthe lateral hole 204. The liquid level sensor 206 always monitorswhether the liquid level of the plating solution is higher than theminimum liquid level or not. When the liquid level of the platingsolution is lower than the minimum liquid level, the flow controller 61a disposed on the plating solution discharge pipe 60 a regulates theplating solution to thus maintain the liquid level of the platingsolution.

[0114] Further, a vertical stream regulating ring 62 for damming off aflow of the plating solution 45 directed outwardly along the horizontaldirection is provided in the plating chamber 49. A horizontal streamregulating ring 63 having an outer circumferential end fixed to theplating container 50 is provided in the plating chamber 49. The verticalstream regulating ring 62 is connected to the inner circumferential endof the horizontal stream regulating ring 63.

[0115] The plating solution horizontally ejected from each of theplating solution supply nozzles 53 collides with at the central portionof the plating chamber 49 to form an upward flow and a downward flow.When no substrate is held by the head 47, the upward flow pushes up theliquid surface of the plating solution 45 at the central portion insidethe vertical stream regulating ring 62. When the substrate is lowered,the substrate is firstly brought into contact with the plating solution45 at the central portion pushed up by the upward flow, and hence airbubbles on the lower surface of the substrate are pushed outwardly. Onthe other hand, the downward flow is changed to a horizontal flowflowing from the central portion of the anode 48 to the peripheralportion of the anode 48 to push away peeled fine pieces of the blackfilm formed on the surface of the anode 48. The peeled pieces of theblack film pass from the peripheral portion of the anode 48 through thelower portion of the horizontal stream regulating ring 63 to the firstplating solution discharge ports 57, so that the peeled pieces of theblack film can be prevented from approaching and being attached to thesurface of the substrate to be processed.

[0116] In the electroplating, the current density in the platingsolution governs the thickness of the plated film. Therefore, in orderto make the thickness of the plated film uniform, it is necessary tomake the distribution of the current density in the plating solutionuniform. In the present embodiment, as described below, since theperipheral portion of the substrate has an electrical contact, thecurrent density of the plating solution present on the peripheralportion of the substrate tends to be increased. Therefore, the verticalstream regulating ring 62 is extended vertically to be disposed in thevicinity of the peripheral portion of the substrate, and the horizontalstream regulating ring 63 is extended horizontally outwardly to bedisposed below the vertical stream regulating ring 62, therebyregulating the electric current flowing in the vicinity of theperipheral portion of the substrate. Thus, these stream regulating ringscan reduce local concentration of the electric current and can make thecurrent density of the plating solution uniform to thus prevent theplated film from being thick at the peripheral portion of the substrate.

[0117] In the present embodiment, the vertical stream regulating ringand the horizontal stream regulating ring are used for regulating theelectric current around the peripheral portion of the substrate.However, the present invention is of course not limited to this example.

[0118] On the other hand, the head 47 is provided with a rotatablehousing 70 in a hollow cylindrical form and a disk-shaped substratetable 71 for holding a substrate W on its lower surface which table 71is rotated together with the housing 70. A ring-shaped substrate holdingmember 72 projecting radially inwardly is provided at the lower end ofthe housing 70. For example, the substrate holding member 72 is formedof a packing material and has a tapered surface on a part of its innercircumferential surface for guiding the substrate W. The peripheralportion of the substrate W is held between the substrate holding member72 and the substrate table 71. The substrate table 71 is constituted asa pressing member for pressing the substrate W against the substrateholding member 72.

[0119]FIG. 5 is an enlarged view showing a part of the head 47. As shownin FIG. 5, a ring-shaped lower sealing member 73 is mounted on thesubstrate holding member 72. The lower sealing member 73 projectsinwardly, and the front end of its upper surface projects upwardly in anannular tapered form. An upper sealing member 74 is mounted on theperipheral portion of the lower surface of the substrate table 71. Apart of the upper sealing member 74 projects downwardly from the lowersurface of the substrate table 71. Thus, when the substrate W is held bythe substrate holding member 72, the lower surface of the substrate W isbrought into pressure contact with the lower sealing member 73, and theupper surface of the substrate W is brought into pressure contact withthe upper sealing member 74, thereby reliably sealing the platingchamber 49.

[0120] In the present embodiment, eighty air vent holes 75 having adiameter of 3 mm are formed in the substrate holding member 72 at equalintervals along the circumferential direction. Each of the air ventholes 75 is extended horizontally outwardly and further extendedoutwardly in an upwardly inclined state. The air vent holes 75 areprovided in such a state that, when the head 47 is located in theplating position as shown in FIG. 4, about half of the peripheralopening end of the air vent hole 75 is exposed to the exterior from theliquid surface of the plating solution 45 in the plating chamber 49. Asdescribed above, the upward flow of the plating solution 45 in theplating chamber 49 is brought into contact with the substrate W to sweepaway air bubbles to the exterior from the central portion of thesubstrate W. Accordingly, the air bubbles swept by the upward flow aresuccessively discharged to the exterior through the air vent holes 75.Thus, air bubbles can be prevented from remaining between the substrateW and the surface of the plating solution 45.

[0121] For example, the angle θ of inclination of the air vent holes 75is set to be 30°. When the venting of air is taken into consideration,the air vent holes 75 should preferably have a diameter of 2 mm to 5 mm,and more preferably about 3 mm. Further, the air vent holes 75 shouldpreferably be inclined upwardly in the outward direction at an angle ofnot less than 20°, and more preferably about 30°.

[0122] Further, the peripheral opening end of the air vent holes 75 maybe located fully above the liquid surface of the plating solution at thetime of plating. The air vent holes 75 may be branched into two holes,one of which is opened in the vicinity of the liquid surface, and theother of which is opened at a position fully above the liquid surface.It has been confirmed that, when a gap S between the lower surface ofthe substrate W held on the lower surface of the substrate table 71 andthe upper end of the air vent holes 75 is not more than about 1.5 mm,air can be vented in a short time.

[0123] Each of the air vent holes 75 may be provided in any form, e.g.,in a linear form, or each of the air vent holes 75 may be branchedoutwardly into two holes.

[0124] Further, plate-spring-like contacts 76 for a cathode electrodeare disposed on the substrate holding member 72 in the housing 70. Whenthe substrate W is held on the lower surface of the substrate table 71,the contacts 76 for a cathode electrode energize the substrate W.Feeding contacts (probes) 77 are vertically downwardly provided at theouter circumferential side of the substrate table 71. When the substratetable 71 is lowered, each of the feeding contacts 77 feeds power to eachof the contacts 76 for a cathode electrode. Since the plating solution45 is sealed with a lower sealing member 73 disposed between thesubstrate W and the substrate holding member 72, the contacts 76 for acathode electrode and the feeding contacts 77 can be prevented fromcoming into contact with the plating solution 45.

[0125] In the present embodiment, as shown in FIG. 7, sixcircumferentially divided cathode electrode plates 208 are provided, andeach of the cathode electrode plates 208 is provided with fifteencontacts 76 extended inwardly for a cathode electrode. Power isrespectively fed from each of the feeding contacts 77 to each of thecathode electrode plates 208, thereby making the distribution of thevoltage uniform.

[0126]FIGS. 8 and 9 show the whole structure of the head 47. The head 47has a base 83 mounted on sliders 82, which are vertically movable withrotation of a ball screw, for example, along rails 81 fixed to a fixedframe 80. The housing 70 is rotatably supported on the base 83. On theother hand, the substrate table 71 is connected to the lower end of atable shaft 84 extended concentrically through the interior of a shaftin the housing 70. The table shaft 84 has a spline 85 so as not to berotated so that the housing 70 and the table shaft 84 are rotatedtogether and vertically movable relative to each other.

[0127] A servomotor 86 is mounted on the base 83. A timing belt 89 isprovided between a drive pulley 87 of the servomotor 86 and a drivenpulley 88 fixed to the shaft of the housing 70. Thus, upon energizationof the servomotor 86, the members indicated by solid lines in FIG. 10,i.e., the housing 70, the table shaft 84, and the substrate table 71,with the substrate W being held thereon are rotated together.

[0128] A bracket 90 is vertically mounted on the base 83, and anactuator 91 using air as a drive source is mounted on the bracket 90. Onthe other hand, a connector 95 is connected to the upper portion of thetable shaft 84. The connector 95, the actuator 91, and an actuatorslider 93 are relatively moved in the vertical direction. With thisarrangement, members indicated by solid lines in FIG. 11 (except for theactuator), i.e., the table shaft 84, the substrate table 71 and the likeare vertically movable.

[0129] In order to prevent wear of a rotary joint 94, cause by rotationof the housing 70 at a high speed, an actuator 97 and an actuator slider98 are provided in order that when liquid is removed from the substrateby rotating the housing 70 at a high speed without supplying current tothe substrate, the rotary joint 94 is disengaged from the connector 92.The feeding contacts 77 provided on the substrate table 71 are connectedto a cathode of a power supply for plating through the rotary joint 94.

[0130] Openings 96 are provided in the cylindrical housing 70 forallowing the substrate W and the robot hand to pass therethrough (seeFIGS. 5, 18 to 20).

[0131] Chuck mechanisms 100 for holding the substrate W on the lowersurface of the substrate table 71 are provided on the peripheral portionof the substrate table 71 at three positions in the circumferentialdirection of the substrate table 71. Each of the chuck mechanisms 100has a bell crank-shaped hook 101. As shown in FIGS. 12 and 13, the hook101 is rotatably supported at its central portion by the substrate table71 through a pin 102. A compression coil spring 103 is interposedbetween a lever section 101 a extending in the upper inward direction ofthe pin 102 and the upper surface of the substrate table 71 so as tourge the hook 101 in a closing direction. Thus, normally, by the urgingforce of the coil spring 103, a claw 104 provided on the lower end ofthe hook 101 enters a position under the substrate W to hold thesubstrate W.

[0132] On the other hand, at a position above the lever section 101 a ofthe hook 101, a pusher 106, which is vertically moved by actuation of anair cylinder 105, is mounted on the base 83. Thus, when the substratetable 71 is raised, the pusher 106 is lowered, and the hook 101 isrotated in an opening direction against the urging force of thecompression coil spring 103, thus releasing the substrate W. An opening107 is provided at a position facing the pusher 106 in the housing 70 sothat the vertical movement of the pusher 106 is allowed.

[0133] In this case, when the substrate table 71 is in an upperposition, the hook 101 serves to hold the substrate W on the lowersurface of the substrate table 71. On the other hand, when the substratetable 71 is lowered to permit the substrate to be sandwiched and heldbetween the upper sealing member 74 of the substrate table 71 and thelower sealing member 73 of the housing 70, adjustment is made so thatthe hook 101 contacts the substrate table 71 and thus is separated fromthe substrate W to create a minute gap between the hook 101 and thesubstrate W, whereby the substrate W is not held by the hook 101.

[0134]FIGS. 14 and 15 show the inverter 20 provided in each of thepre-treatment unit 21, the first substrate stage 23 b, and the secondsubstrate stage 26 b. The inverter 20 comprises a seal case 110 which isrotated by energization of a motor (not shown), a pair of arc-shapedhands 111 which are opened or closed by means of a link mechanism or thelike housed within the seal case 110, and chuck rollers 113 which arerotatably mounted on shafts 112 and vertically provided on the hands 111to hold the peripheral edge of the substrate W. The plane defined by thechuck rollers 113 is located at a position which is offset by a distancee from an axis of the seal case 110.

[0135] With this construction, when the hands 111 hold the substrate Wand are inverted, the substrate W can be vertically moved by a distance2 e, which is twice the distance e. Thus, when a slit, through which adrive section of the inverter 20 passes, is formed in a splashpreventive cover in the pre-treatment unit 21, this opening can beprovided above the position of the substrate chuck of the pre-treatmentunit 21.

[0136] Next, a series of plating processes using the plating apparatusaccording to this embodiment will be described.

[0137] A cassette housing a plurality of substrates whose surfaces(surface on which semiconductor elements are formed, i.e., surface to beprocessed) face upward is placed on a cassette stages 15 within thehousing unit 10. The recess-type hand of the first transfer device 17 isinserted into the cassette and holds the substrate, and then takes outthe substrate from the cassette. The first transfer device 17 whichholds the substrate by the hand rotates about its own axis and transfersthe substrate onto the second substrate stage 26 a. Next, the thirdtransfer device 27 holds the substrate placed on the second substratestage 26 a by the recess-type hand, rotates about its own axis, and thentransfers the substrate onto the first substrate stage 23 a.

[0138] The second transfer device 24 moves to a position close to thefirst substrate stage 23 a, and holds the substrate placed on the firstsubstrate stage 23 a by the recess-type hand. Thereafter, the secondtransfer device 24 holding the substrate rotates toward thepre-treatment unit 21, and transfers the substrate to the substratechuck of the pre-treatment unit 21 through a slit formed in the splashpreventive cover for allowing the substrate to pass therethrough.

[0139] In the substrate chuck of the pre-treatment unit 21, fingers areopened, and the substrate is positioned between the fingers, and thenthe fingers are closed to hold the substrate. Next, a pre-treatmentliquid nozzle, which has been in the stand-by position so as not tohinder the movement of the hands 111 of the inverter 20, is rotated to aposition above and near the center of the substrate. While the substratechuck holding the substrate is rotated at a medium speed of, forexample, about 300 min⁻¹, the pre-treatment liquid is supplied throughthe pre-treatment liquid nozzle onto the substrate. When the liquid hasbeen speedily spread over the entire surface of the substrate, therotational speed of the substrate is increased to remove excessivepre-treatment liquid on the substrate under a centrifugal force.

[0140] After the removal of the liquid from the substrate is completedand the substrate chuck is stopped, the hands 111 of the inverter 20 arelowered. The hands 111 hold the substrate, and the fingers of thesubstrate chuck in the pre-treatment unit 21 are opened to transfer thesubstrate to the inverter 20 completely. The inverter 20 is raised to aposition where the hands 111 of the inverter 20 do not contact thesubstrate chuck while an inverting operation is performed. Thereafter,the hands 111 of the inverter 20 and the substrate are rotated by anangle of 180 degrees about the horizontal inverting axis, and thesurface of the substrate faces downwardly. The inverter 20 is lowered toa position where the substrate is transferred to the second transferdevice 24, and then stopped.

[0141] The hands 111 of the inverter 20 are located at a position belowthe inverting axis when the hands 111 receive the substrate from thethird transfer device 27 and receives the substrate from the substratechuck after the pre-treatment. On the other hand, when the hands 111 areinverted about the inverting axis to transfer the substrate to thesecond transfer device 24, the hands 111 are located at a position abovethe inverting axis.

[0142] The second transfer device 24 inserts the recess-type hand intothe splash preventive cover through the slit formed in the cover. Thesubstrate is held by the hands of the inverter 20. The recess-type handis positioned so as to allow the hand to contact the lower peripheraledge portion of the substrate. The hands 111 of the inverter 20 releasethe substrate, and the recess-type hand of the second transfer device 24holds the substrate with its surface facing downwardly. The secondtransfer device 24 takes out the substrate from the pre-treatment unit21, and moves to one predetermined plating unit 22.

[0143] The housing 70 and the substrate table 71 in the plating unit 22are raised by raising the base 83 to a position where the substrate isattached or detached. The substrate table 71 is further lifted by meansof the actuator 91 to the upper end of the housing 70. The air cylinders105 are actuated to lower the pushers 106 to thereby release three hooks101 provided on the peripheral portion of the substrate table 71.

[0144] The second transfer device 24 inserts the hand and the substrateinto the housing 70 through the opening 96 formed in the housing 70, andlifts the hand to a position immediately below the substrate table 71.In this state, the pushers 106 are raised, and the hooks 101 are closedby the urging forces of the compression coil springs 103 providedbetween the lever sections 101 a of the hooks 101 and the upper surfaceof the substrate table 71 to thus hold the substrate. After thesubstrate is held by the hooks 101, the hand of the second transferdevice 24 is slightly lowered and withdrawn through the opening 96 ofthe housing 70.

[0145] Next, the substrate table 71 is lowered by the actuator 91, andthe substrate is centered by the tapered portion on the inner side ofthe substrate holding member 72 in the housing 70, placed on the lowersealing member 73 of the substrate holding member 72, and furtherpressed against the upper sealing member 74 near the peripheral portionof the substrate table 71 to form a seal for preventing the platingsolution from entering the electrode contact side. At the same time, thesubstrate table 71 is lowered to press the feeding contacts 77 againstthe contacts 76 for a cathode electrode, thereby achieving reliablecontacts.

[0146] In this case, the hooks 101 hold the substrate in such a mannerthat the substrate is placed on the hooks 101. When the substrate table71 is raised from the housing 70, the substrate is held by the uppersealing member 74 to such an extent that play does not occur. On theother hand, when the substrate table 71 is lowered, and the substrate issealed by the lower sealing member 73 and the upper sealing member 74,the substrate is stably held therebetween by allowing the upper sealingmember 74 to be deformed. In this case, the hooks 101 are stopped by thesubstrate table 71 and are in a position slightly away from thesubstrate W so that the hooks 101 do not hold the substrate. Therefore,the substrate is equally held by the lower sealing member 73 and theupper sealing member 74 without the influence of the three hooks 101.

[0147] In this state, when the plating solution is ejected through theplating solution supply nozzles 53 in the plating process container 46,the liquid surface in its center portion rises. At the same time, whilethe servomotor 86 is energized to rotate the housing 70, the substrate Wand the substrate table 71 at a medium speed of, for example, 150 min⁻¹,the base 83 is lowered by a ball screw or the like. The rotational speedof the substrate is preferably about 100 to 250 min⁻ from the viewpointof the removal of air. In this case, after the central portion of thesubstrate comes into contact with the surface of the plating solution45, the area of contact between the substrate and the raised liquidsurface increases gradually, and then the plating solution 45 reachesthe periphery of the substrate. In the periphery of the lower surface ofthe substrate, the lower sealing member 73 projects from the substratesurface, and hence air is likely to be left on the periphery of thelower surface of the substrate. However, by allowing the platingsolution containing air bubbles to flow to the exterior through air ventholes 75 by the rotation of the housing 70, air bubbles present on thelower surface of the substrate can be removed. Thus, air bubbles on thelower surface of the substrate can be completely removed, and uniformplating can be realized. The predetermined position where the substrateis plated is such that the substrate is immersed in the plating solution45 within the plating chamber 49 and the plating solution does not enterthe housing 70 through the openings 96 of the housing 70.

[0148] When the substrate is lowered to a predetermined position, thehousing 70 is rotated at a medium speed for several seconds to removeair. The rotational speed of the housing 70 is then changed to a lowrotational speed of, for example, 100 min⁻¹, and current flows forelectroplating by utilizing the above anode and the treating face of thesubstrate as the cathode. In this case, the rotational speed is in therange of, for example, 0 to 225 min⁻¹. During the plating process, theplating solution is continuously fed at a predetermined flow ratethrough the plating solution supply nozzles 53, is discharged throughthe first plating solution discharge ports 57 and the second platingsolution discharge ports 59, and is circulated through the platingsolution regulating tank 40. In this case, since the plating thicknessis determined by the current density and the current feed time, thecurrent feed time (plating time) is set according to a desired amount ofdeposition.

[0149] This plating time is, for example, 120 to 150 seconds. Theplating process is carried out, for example, at about 1 A (ampere) forabout 40 seconds, and then, for example, at about 7.4 A for remainingtime.

[0150] After the completion of the feed of current, the base 83 israised to lift the housing 70, the substrate W and the substrate table71 to a position above the surface of the plating solution 45 within theplating chamber 49 and below the upper end of the plating processcontainer cover. Then, the substrate is rotated at a high speed of, forexample, 500 to 800 min⁻¹ to remove the plating solution from thesubstrate under centrifugal force. After the completion of the removalof the liquid from the substrate, the rotation of the housing 70 isstopped so that the housing 70 faces a predetermined direction. The base83 is then raised to lift the housing 70 to a position where thesubstrate is attachable or detachable. After the housing 70 is lifted tothe position where the substrate is attachable or detachable, thesubstrate table 71 is further raised by the actuator 91 to a positionwhere the substrate is attachable or detachable.

[0151] When the surface of the plating solution is raised, the feed rateof the plating solution is about 10 to 30 liters/min (preferably 20liters/min), and the plating solution is discharged through the firstplating solution discharge ports 57 at a rate of about 3 to 6 liters/min(preferably 5 liters/min). During plating, the feed rate of the platingsolution is about 8 to 20 liters/min (preferably 10 liters/min), and theplating solution is discharged through the first plating solutiondischarge ports 57 at a rate of about 3 to 6 liters/min (preferably 5liters/min), and through the second plating solution discharge ports 59at a rate of about 3 to 6 liters/min (preferably 5 liters/min). When theliquid level is lowered after plating, the feed rate of the platingsolution is about 15 to 30 liters/min (preferably 20 liters/min), andthe plating solution is discharged through the first plating solutiondischarge ports 57 at a rate of about 20 to 30 liters/min (preferably 25liters/min). During stopping of the plating process for a long period oftime, the plating solution is fed at a rate of about 2 to 4 liters/min(preferably 3 liters/min), and entirely flows and circulates through thesecond plating solution discharge ports 59.

[0152] Next, the hand of the second transfer device 24 is inserted intothe housing 70 through the opening 96 of the housing 70, and is raisedto a position where the hand receives the substrate. The pushers 106 arethen lowered to push the lever sections 101 a of the hooks 101 and openthe hooks 101, whereby the substrate held by the hooks 101 is dropped onthe recess-type hand. In this state, the hand is slightly lowered, andthe hand and the substrate held by the hand are taken out through theopening 96 of the housing 70. The substrate is held in such a mannerthat the surface of the substrate faces downwardly and only theperipheral edge of the substrate is brought into contact with the hand,as with mounting the substrate with the hand.

[0153] The substrate held by the second transfer device 24 istransferred to the inverter 20 in the first substrate stage 23 b in sucha state that the surface of the substrate faces downwardly. The inverter20 holds the periphery of the substrate by the two hands 111, andultrapure water is supplied to both surfaces of the substrate to rinsethe substrate. And then the substrate is rotated by 180 degrees aroundthe horizontal inverting axis so that the surface of the substrate facesupwardly. Next, the third transfer device 27 holds the substrate placedon the inverter 20 in the first substrate stage 23 b by the hand, andtransfers the substrate to the chemical liquid cleaning unit 25.

[0154] In the chemical liquid cleaning unit 25, the substrate is held bysix fingers, and the substrate is rotated so that the surface of thesubstrate faces upwardly, and then the surface, edge and backside of thesubstrate are cleaned with a chemical liquid. After the completion ofcleaning of the substrate with the chemical liquid, the substrate isrinsed with ultrapure water, and then the substrate held by the fingersis rotated at a high speed to remove the liquid from the substrate.

[0155] After the completion of the removal of the liquid from thesubstrate, the third transfer device 27 takes out the substrate with thehand in such a state that the surface of the substrate faces upwardly.The substrate is then placed on the second substrate stage 26 b. In thesecond substrate stage 26 b, the substrate is further rinsed withultrapure water.

[0156] Next, the first transfer device 17 receives the substrate fromthe second substrate stage 26 b with the hand, and transfers thesubstrate to the cleaning and drying unit 16. In the cleaning and dryingunit 16, the surface and backside of the substrate are rinsed withultrapure water such as deionized water, and then the substrate isrotated at a high speed to remove the liquid from the substrate and thento be dried. The first transfer device 17 holds the substrate with thehand in such a manner that the surface of the substrate faces upwardly,and transfers the substrate at a predetermined position in the cassetteon the cassette stage 15.

[0157]FIG. 16 shows an essential part of the plating apparatus accordingto the second embodiment of the present invention. This embodiment isdifferent from the first embodiment in the following: A labyrinth seal212 comprising a large number of grooves 210 arranged in parallel isprovided around the inlet of the anode support 52 which is removablymounted in the plating container 50 through a knob 51 and holds an anode48. An inert gas introduction passage 214 for introducing inert gas suchas nitrogen gas is connected to one of the grooves 210, first ends ofplating solution return passages 216 are connected to the bottoms of allthe grooves 210, and the other ends of the plating solution returnpassages 216 are connected to a plating solution reservoir 218 whichstores overflowed plating solution and is open to the air. The remainingconstruction is the same as that of the first embodiment.

[0158] Thus, the provision of the labyrinth seal 212 comprising aplurality of grooves 210 around the inlet of the anode support 52 in theplating container 50 can eliminate the need to tighten the sealingmember 200 with large force, and can ensure reliable sealing of the gapbetween the plating container 50 and the anode support 52 to prevent theplating solution from leaking out. The inert gas introduction passage214 is connected to one of the grooves 210, the plating solution returnpassages 216 are connected to the bottoms of all the grooves 210, andinert gas, such as nitrogen gas, having a pressure high enough todischarge the plating solution remaining within the grooves 210 isintroduced to the groove 210 through the inert gas introduction passage214. Thus, the plating solution remaining within the grooves 210 can bedischarged to the exterior, and deterioration in the effect of thelabyrinth seal 212 by the plating solution remaining within the groove210 can be prevented.

[0159] In this embodiment, the labyrinth seal 212 comprising a pluralityof grooves 210 is provided on the plating container side. Alternatively,the labyrinth seal may be provided on the anode support side or on boththe plating container side and the anode support side.

[0160]FIG. 17 schematically shows a plating unit in the platingapparatus according to the third embodiment of the present invention. Inthe plating unit of the first embodiment, the transfer of the substrateis performed by moving the housing 70 up and down. In the plating unitof the third embodiment, the liquid level of the plating solution withinthe plating process container is raised or lowered to transfer thesubstrate without the vertical movement of the housing 70.

[0161] When this plating unit is provided, the second transfer device 24shown in FIG. 2, which is a mobile type and rotatable, may have asuction-type hand which holds the substrate by suction, and is rotatableto change the suction surface of the suction-type hand t face upwardlyor downwardly.

[0162] The plating unit according to this embodiment will be describedbelow. The parts or components identical to or corresponding to theparts or components in the plating units according to the aboveembodiments are denoted by the same reference numerals, and a part ofthe explanation thereof will be omitted.

[0163] The plating unit 22 comprises a plating process container 46 anda head 47. The plating container 50 in the plating process container 46has first plating solution discharge ports (not shown) which are locatedaround the anode 48 and are opened at the bottom of the platingcontainer 50, and second plating solution discharge ports 59 fordischarging the plating solution 45 which has overflowed a weir member58 in the plating container 50. Further, the plating container 50 hasthird plating solution discharge ports 120 which are open at a stepportion 50 a provided in the circumferential wall of the weir member 58.A shut-off valve 122 is provided in a plating solution discharge pipe121 extending from the third plating solution discharge ports 120 to thereservoir 226 (see FIG. 22).

[0164] With this construction, a plane defined by the upper end of theweir member 58 in the plating container 50 constitutes a liquid level Afor plating, while a plane defined by the step portion 50 a constitutesa liquid level B for transferring the substrate. Specifically, at thetime of plating process, the shut-off-valve 122 is closed, and theplating solution is ejected through the plating solution supply nozzles53 to raise the liquid level of the plating solution 45 within theplating chamber 49, and overflows the upper end of the weir member 58 inthe plating container 50, thereby maintaining the liquid level at theliquid level A for plating. After the completion of the plating process,the shut-off valve 122 is opened to discharge the plating solution 45within the plating chamber 49 through the third plating solutiondischarge ports 120, thereby bringing the liquid level to the liquidlevel B for transferring the substrate.

[0165] Thus, by immersing the anode 48 in the plating solution 45 over aperiod other than during the plating process, a black film formed on thesurface of the anode 48 can be prevented from being dried and oxidized,and the plating process can be stably carried out.

[0166] When the substrate W is held by the substrate holding member 72provided at the lower end of the housing 70, the housing 70 of the head47 is not vertically movable, but is rotatable about its own axis, andthe substrate W is located at a position between the liquid level A forplating and the liquid level B for transferring the substrate. Thesubstrate table 71 is not provided with any means for holding thesubstrate, and the substrate W is placed on the substrate holding member72 of the housing 70, and then the substrate table 71 is lowered tosandwich the peripheral portion of the substrate W between the substrateholding member 72 and the lower peripheral portion of the substratetable 71, thereby holding the substrate W.

[0167] Next, a plating process performed by the plating apparatusaccording to this embodiment will be described below. This embodiment issubstantially the same as the first embodiment, except for transfer ofthe substrate through the second transfer device 24 and the process inthe plating unit 22. Therefore, only the different construction andoperation will be described.

[0168] First, the substrate placed on the first substrate stage 23 a insuch a manner that the surface of the substrate faces upwardly istransferred to the pre-treatment unit 21 in the following manner: Thesecond transfer device 24 holds the substrate in such a manner that thesuction-type hand with the suction surface facing upward attracts thebackside of the substrate by suction, and rotates toward thepre-treatment unit 21. The substrate and the suction-type hand areinserted into the pre-treatment unit 21 through a slit formed in thesplash preventive cover in the pre-treatment unit 21, and the substrateis positioned between two opened hands 111 of the inverter 20 in thepre-treatment unit 21.

[0169] Further, the second transfer device 24 receives the substratefrom the pre-treatment unit 21 in the following manner: The suction-typehand of the second transfer device 24 with the suction surface facingdownward is inserted into the pre-treatment unit 21 through the slit ofthe splash preventive cover in the pre-treatment unit 21. Thesuction-type hand is then positioned immediately above the substrateheld by the hands 111 of the inverter 20 in the pre-treatment unit 21.The suction-type hand attracts the backside of the substrate by vacuumsuction, and the hands 111 of the inverter 20 are opened. Thus, thesubstrate with the surface facing downward is held completely by thesuction-type hand of the second transfer device 24.

[0170] The substrate is transferred to the plating unit 22 in thefollowing manner: The suction-type hand of the second transfer device 24and the substrate W held by the suction-type hand in such a manner thesurface of the substrate faces downwardly, are inserted into the housing70 through the opening 96 of the housing 70. The suction-type hand isthen moved downwardly, and the vacuum suction is released to place thesubstrate W on the substrate holding member 72 of the housing 70.Thereafter, the suction-type hand is raised and withdrawn from thehousing 70. Next, the substrate table 71 is lowered to sandwich theperipheral portion of the substrate W between the substrate holdingmember 72 and the lower peripheral portion of the substrate table 71,thereby holding the substrate W.

[0171] Thereafter, the plating solution discharge pipe 121 connected tothe third plating solution discharge ports 120 are closed by theshut-off valve 122, and the plating solution is ejected through theplating solution supply nozzles 53. At the same time, the housing 70 andthe substrate W held by the housing 70 are rotated at a medium speed.After the plating solution reaches a predetermined level and severalseconds have elapsed, the rotational speed of the housing 70 is changedto a low rotational speed of, performing electroplating by utilizing theanode 48 as the anode and the processing face of the substrate as thecathode.

[0172] After the completion of the supply of current, the shut-off valve122 is opened to discharge, through the third plating solution dischargeports 120, the plating solution 45 present at a position above the stepportion 50 a to the reservoir. Thus, the housing 70 and the substrateheld by the housing 70 are located above the liquid level of the platingsolution and exposed to the atmosphere. In the state that the housing 70and the substrate W held by the housing 70 are located above the liquidlevel of the plating solution, the housing 70 and the substrate arerotated at a high speed of, for example, 500 to 800 min⁻ to remove theplating solution from the substrate under a centrifugal force. After thecompletion of the removal of the plating solution from the substrate,the rotation of the housing 70 is stopped at a position where thehousing 70 faces a predetermined direction.

[0173] After the rotation of the housing 70 is completely stopped, thesubstrate table 71 is raised to a position where the substrate isdetached or attached. Next, the suction-type hand of the second transferdevice 24 with the suction surface facing downwardly is inserted intothe housing 70 through the opening 96 of the housing 70, and is loweredto a position where the suction-type hand can hold the substrate bysuction. The substrate is then held by vacuum suction by thesuction-type hand, and the suction-type hand is then moved to a positionabove the opening 96 of the housing 70. Thereafter, the suction-typehand and the substrate held by the suction-type hand are withdrawn fromthe housing 70 through the opening 96 of the housing 70.

[0174] According to this embodiment, the mechanism of the head 47 can besimplified and compact. In addition, the plating process is carried outwhen the surface of the plating solution within the plating processcontainer 46 is on a liquid level A for plating, while the substrate isdewatered and transferred when the surface of the plating solution is ona liquid level B for transferring the substrate. Further, it is possibleto prevent a black film formed on the surface of the anode 48 from beingdried and oxidized. Further, since the position of the substrate whichis plated is the same as the position of the substrate from which anexcessive plating solution is removed by rotation of the substrate, theposition for performing mist-splash prevention can be lowered.

[0175] Furthermore, in this embodiment, the following process may beperformed: When the surface of the plating solution is on the liquidlevel B for transferring the substrate, the substrate W is inserted intothe housing 70 and held by the housing 70, and then the liquid level ofthe plating solution is raised to the liquid level A for plating. At thesame time, the housing 70 is raised by a certain distance. After thesurface of the polishing solution is raised to the liquid level A forplating, the housing 70 is rotated at a medium speed of, for example,150 min⁻ and lowered, whereby the substrate W is brought into contactwith the surface of the plating solution which rises at its centralportion. Thus, air bubbles on the surface of the substrate can bepositively removed therefrom.

[0176]FIG. 18 shows a plating unit in the plating apparatus according tothe fourth embodiment of the present invention. The construction of thisembodiment is substantially the same as that of the third embodiment,except that a pressing ring 130 is used, instead of the substrate table71 constituting a pressing member for pressing the substrate against thesubstrate holding member in the third embodiment, and actuators 131 suchas a cylinder for vertically moving the pressing ring 130 are housed inthe housing 70.

[0177] According to this embodiment, when the actuators 131 are actuatedto lower the pressing ring 130, the peripheral portion of the substrateis sandwiched between the substrate holding member 72 of the housing 70and the lower surface of the pressing ring 130, and hence the substrateW is held. The substrate can be released by raising the pressing ring130.

[0178]FIG. 19 shows a plating unit in the plating apparatus according tothe fifth embodiment of the present invention. The construction of thisembodiment is substantially the same as that of the third embodiment,except that a clamp mechanism 141 having swing links 142 is used,instead of the substrate table 71 constituting a pressing member forpressing the substrate against the substrate holding member in the thirdembodiment, and the clamp mechanism 141 is housed within the housing 70in its lower part.

[0179] According to this embodiment, when the swing links 142 are swunginward through the clamp mechanism 141 so as to be located in thehorizontal direction, the peripheral portion of the substrate issandwiched between the substrate holding member 72 of the housing 70 andthe swing links 142, and hence the substrate W is held. When the swinglinks 142 are swung outward so as to be located in the verticaldirection, the substrate is released. At the same time, it is possibleto prevent the swing links 142 from hindering the withdrawal of thesubstrate W.

[0180]FIG. 20 shows a plating unit in the plating apparatus according tothe sixth embodiment of the present invention. The construction of thisembodiment is substantially the same as that of the third embodiment,except that an elastic member 150 which is elastically deformable, i.e.,expandable or contractable by pneumatic pressure is used, instead of thesubstrate table 71 constituting a pressing member for pressing thesubstrate against the substrate holding member in the third embodiment.This elastic member 150 is housed within the housing 70 in its lowerpart.

[0181] According to this embodiment, by expanding the elastic member 150by pneumatic pressure, the peripheral portion of the substrate issandwiched between the substrate holding member 72 of the housing 70 andthe elastic member 150, and hence the substrate W is held. The substratecan be released by discharging air from the elastic member 150. At thesame time, it is possible to prevent the elastic member 150 fromhindering the withdrawal of the substrate W.

[0182]FIG. 21 shows the whole construction of a plating unit in theplating apparatus according to the seventh embodiment of the presentinvention. FIG. 22 shows a flow diagram of a plating solution in aplating apparatus having a plurality of the plating units. The parts orcomponents identical to or corresponding to the parts or components inthe plating units according to the above embodiments are denoted by thesame reference numerals, and a part of the explanation thereof will beomitted.

[0183] As shown in FIG. 21, the plating unit is composed mainly of aplating process container 46 which is substantially cylindrical andcontains a plating solution 45 therein, and a head 47 disposed above theplating process container 46 for holding the substrate W. In FIG. 21,the plating unit is in such a state that the substrate W is held by thehead 47 and the surface of the plating solution 45 is on the liquidlevel for plating.

[0184] The plating process container 46 has a plating chamber 49 whichis open upward and has an anode 48 at the bottom thereof. A platingcontainer 50 containing the plating solution 45 is provided within theplating chamber 49. Plating solution supply nozzles 53, which projecthorizontally toward the center of the plating chamber 49, are disposedat circumferentially equal intervals on the inner circumferential wallof the plating container 50. The plating solution supply nozzles 53communicate with plating solution supply passages 54 (see FIG. 4)extending vertically within the plating container 50.

[0185] As shown in FIG. 22, the plating solution supply passages 54 areconnected to the plating solution regulating tank 40 (see FIG. 3)through the plating solution supply pipes 55. Control valves 56 forcontrolling the back pressure so as to be constant are disposed on eachof the plating solution supply pipes 55.

[0186] Further, according to this embodiment, a punch plate 220 having alarge number of holes with a size of, for example, about 3 mm isdisposed at a position above the anode 48 within the plating chamber 49.The punch plate 220 prevents a black film formed on the surface of theanode 48 from curling up due to the plating solution 45 and consequentlybeing flowed out.

[0187] The plating container 50 has first plating solution dischargeports 57 for withdrawing the plating solution 45 contained in theplating chamber 49 from the peripheral portion of the bottom in theplating chamber 49, and second plating solution discharge ports 59 fordischarging the plating solution 45 which has overflowed a weir member58 provided at the upper end of the plating container 50. Further, theplating container 50 has third plating solution discharge ports 120 fordischarging the plating solution before overflowing the weir member 58.The plating solution which has flowed through the second platingsolution discharge ports 59 and the third plating solution dischargeports 120 join at the lower end of the plating container 50, and then isdischarged from the plating container. Instead of providing the thirdplating solution discharge ports 120, as shown in FIGS. 27A through 27D,the weir member 58 may have, in its lower part, openings 222 having apredetermined width at predetermined intervals so that the platingsolution 45 passes through the openings 222 and is then discharged tothe second plating solution discharge ports 59.

[0188] With this arrangement, when the amount of plating solutionsupplied is large during plating, the plating solution is discharged tothe exterior through the third plating solution discharge ports 120 oris passed through the openings 222 and discharged to the exteriorthrough the second plating solution discharge ports 59 and, in addition,as shown in FIG. 27A, the plating solution overflows the weir member 58is discharged to the exterior through the second plating solutiondischarge ports 59. On the other hand, during plating, when the amountof plating solution supplied is small, the plating solution isdischarged to the exterior through the third plating solution dischargeports 120, or alternatively as shown in FIG. 27B, the plating solutionis passed through the openings 222 and discharged to the exteriorthrough the second plating solution discharge ports 59. In this manner,this construction can easily cope with the case where the amount ofplating solution supplied is large or small.

[0189] Further, as shown in FIG. 27D, through holes 224 for controllingthe liquid level, which are located above the plating solution supplynozzles 53 and communicate with the plating chamber 49 and the secondplating solution discharge ports 59, are provided at circumferentiallypredetermined pitches. Thus, when plating is not performed, the platingsolution is passed through the through holes 224, and is discharged tothe exterior through the second plating solution discharge ports 59,thereby controlling the liquid level of the plating solution. Duringplating, the through holes 224 serve as an orifice for restricting theamount of the plating solution flowing therethrough.

[0190] As shown in FIG. 22, the first plating solution discharge ports57 are connected to the reservoir 226 through the plating solutiondischarge pipe 60 a, and a flow controller 61 a is provided in theplating solution discharge pipe 60 a. The second plating solutiondischarge ports 59 and the third plating solution discharge ports 120join with each other within the plating container 50, and the joinedpassage is then connected directly to the reservoir 226 through theplating solution discharge pipe 60 b.

[0191] The reservoir 226 is constructed so that the the reservoir 226.The plating solution which has flowed into the reservoir 226 isintroduced by a pump 228 into the plating solution regulating tank 40(see FIG. 3). This plating solution regulating tank 40 is provided witha temperature controller 230 and a plating solution analyzing unit 232for sampling the plating solution and analyzing the sample solution.When a single pump 234 is operated, the plating solution is suppliedfrom the plating solution regulating tank 40 through the filter 236 tothe plating solution supply nozzles 53 in each of the plating units. Acontrol valve 56 is provided in the plating solution supply pipe 55extending from the plating solution regulating tank 40 to each of theplating units. This control valve 56 serves to make the pressure on thesecondary side constant, and, even when one plating unit is stopped, thecontrol valve 56 can make the supply pressure of the plating solution inthe other plating units constant.

[0192] Thus, a plating solution prepared in a plating solutionregulating tank 40 in a single plating process system is fed to aplurality of plating units through a single pump 234. The platingsolution preparation tank 40 having a large capacity is used in theplating process system to prepare a plating solution. With thisarrangement, the plating solution is fed to each of the plating unitswhile controlling the flow rate in each of the plating units throughcontrol valves 56, and a variation in quality of the plating solutioncan be suppressed.

[0193] A vertical stream regulating ring 62 and a horizontal streamregulating ring 63 are disposed within the plating chamber 49 at aposition near the internal circumference of the plating chamber 49, andthe central portion of the liquid surface is pushed up by an upwardstream out of two divided upward and downward streams of the platingsolution 45 within the plating chamber 49, whereby the downward flow issmoothened and the distribution of the current density is further madeuniform. The horizontal stream regulating ring 63 has a peripheralportion which is fixed to the plating container 50, and the verticalstream regulating ring 62 is connected to the horizontal streamregulating ring 63.

[0194] On the other hand, the head 47 comprises a housing 70 which is arotatable and cylindrical receptacle having a downwardly open end andhas openings 96 on the circumferential wall, and vertically movable rods242 having, at their lower end, a pressing ring 240. As shown in FIG.26, an inwardly projecting ring-shaped substrate holding member 72 isprovided at the lower end of the housing 70. A ring-shaped sealingmember 244 is mounted on the substrate holding member 72. Thering-shaped sealing member 244 projects inward, and the front end of thetop surface in the ring-shaped sealing member 244 projects upward in anannular tapered form. Further, contacts 76 for a cathode electrode aredisposed above the sealing member 244. Air vent holes 75, which extendoutwardly in the horizontal direction and further extend outwardly in anupwardly inclined state, are provided in the substrate holding member 72at circumferentially equal intervals. The contacts 76 for a cathodeelectrode and the air vent holes 75 are the same as those in the firstembodiment.

[0195] With this arrangement, as shown in FIG. 23, the liquid level ofthe plating solution is lowered, and as shown in FIGS. 25 and 26, thesubstrate W is held by a robot hand H or the like, and inserted into thehousing 70 where the substrate W is placed on the upper surface of thesealing member 244 of the substrate holding member 72. Thereafter, therobot hand H is withdrawn from the housing 70, and the pressing ring 240is then lowered to sandwich the peripheral portion of the substrate Wbetween the sealing member 244 and the lower surface of the pressingring 240, thereby holding the substrate W. In addition, upon holding ofthe substrate W, the lower surface of the substrate W is brought intopressure contact with the sealing member 244 to seal this contactportion positively. At the same time, current flows between thesubstrate W and the contacts 76 for a cathode electrode.

[0196] Returning to FIG. 21, the housing 70 is connected to an outputshaft 248 of a motor 246, and rotated by energization of the motor 246.The pressing rods 242 are vertically provided at predetermined positionsalong the circumferential direction of a ring-shaped support frame 258rotatably mounted through a bearing 256 on the lower end of a slider254. The slider 254 is vertically movable by actuation of a cylinder252, with a guide, fixed to a support 250 surrounding the motor 246.With this construction, the pressing rods 242 are vertically movable bythe actuation of the cylinder 252, and, in addition, upon the holding ofthe substrate W, the pressing rods 242 are rotated integrally with thehousing 70.

[0197] The support 250 is mounted on a slide base 262 which isvertically movable by a ball screw 261 rotated by energization of themotor 260. The support 250 is surrounded by an upper housing 264, and isvertically movable together with the upper housing 264 by energizationof the motor 260. Further, a lower housing 257 for surrounding thehousing 70 during plating is mounted on the upper surface of the platingcontainer 50.

[0198] With this construction, as shown in FIG. 24, maintenance can beperformed in such a state that the support 250 and the upper housing 264are raised. A crystal of the plating solution is likely to deposit onthe inner circumferential surface of the weir member 58. However, whenthe support 250 and the upper housing 264 are raised, a large amount ofthe plating solution is made to flow and overflows the weir member 58,and hence the crystal of the plating solution is prevented from beingdeposited on the inner circumferential surface of the weir member 58. Acover 50 b for preventing the splash of the plating solution isintegrally provided in the plating container 50 to cover a portion abovethe plating solution which overflows during plating process. By coatingan ultra-water-repellent material such as HIREC (manufactured by NTTAdvance Technology) on the lower surface of the cover 50 b forpreventing the splash of the plating solution, the crystal of theplating solution can be prevented from being deposited on the cover 50b.

[0199] Substrate centering mechanisms 270 located above the substrateholding member 72 of the housing 70 for performing centering of thesubstrate W are provided at four places along the circumferentialdirection in this embodiment (see FIG. 30).

[0200]FIG. 28 shows the substrate centering mechanism 270 in detail. Thesubstrate centering mechanism 270 comprises a gate-like bracket 272fixed to the housing 70, and a positioning block 274 disposed within thebracket 272. This positioning block 274 is swingably mounted through asupport shaft 276 horizontally fixed to the bracket 272. Further, acompression coil spring 278 is interposed between the housing 70 and thepositioning block 274. Thus, the positioning block 274 is urged by thecompression coil spring 278 so that the positioning block 274 rotatesabout the support shaft 276 and the lower portion of the positioningblock 274 projects inwardly. The upper surface 274 a of the positioningblock 274 serves as a stopper, and is brought into contact with thelower surface 272 a of the bracket 272 to restrict the movement of thepositioning block 274. Further, the positioning block 274 has a taperedinner surface 274 b which is widened outward in the upward direction.

[0201] With this construction, a substrate is held by the hand of atransfer robot or the like, is carried into the housing 70, and isplaced on the substrate holding member 72. In this case, when the centerof the substrate deviates from the center of the substrate holdingmember 72, the positioning block 274 is rotated outwardly against theurging force of the compression coil spring 278 and, upon the release ofholding of the substrate from the hand of the transfer robot or thelike, the positioning block 274 is returned to the original position bythe urging force of the compression coil spring 278. Thus, the centeringof the substrate can be carried out.

[0202]FIG. 29 shows a feeding contact (a probe) 77 for feeding power toa cathode electrode plate 208 of a contact 76 for a cathode electrode(see FIG. 7). This feeding contact 77 is composed of a plunger and issurrounded by a cylindrical protective member 280 extending to thecathode electrode plate 208, whereby the feeding contact 77 is protectedagainst the plating solution.

[0203] In this case, when plating process is carried out, an annularprojecting portion projecting from the inner circumferential surface ofthe sealing member 244 is pressed against the surface, to be plated, ofthe substrate. The inner side of the annular projecting portion isfilled with the plating solution. Therefore, the plating solutionremains in the tip end of the annular projecting portion. This platingsolution, upon drying, becomes a source for particles. For this reason,in this embodiment, a plating solution suction mechanism 300 is providedfor removing the plating solution remaining in the tip end of theannular projecting portion of the sealing member 244.

[0204]FIGS. 30 and 31 show this plating solution suction mechanism 300.The plating solution suction mechanism 300 has a plating solutionsuction nozzle 302 extending in an arc form, for example, having acentral angle of about 100°, along the annular projecting portion on theinner circumferential surface of the sealing member 244. This platingsolution suction nozzle 302 is connected through a block 306 to thelower end of a plating solution suction pipe 304 which has a platingsolution passage 304 a therein and is bent at a right angle from thevertical direction and extends in the horizontal direction. The otherend of the plating solution suction pipe 304 is connected to a flexiblepipe 312 extending from a vacuum source 310.

[0205] The plating solution suction pipe 304 is connected to ahorizontal slider 316 which is moved horizontally by actuating acylinder 314 for horizontal movement. Further, the cylinder 314 forhorizontal movement is connected through a hooked bracket 322 to avertical slider 320 which is vertically moved by actuating a cylinder318 for vertical movement. Further, the cylinder 318 for verticalmovement is mounted on the support 250. Therefore, the plating solutionsuction nozzle 302 is vertically and horizontally movable.

[0206] In the case where the plating solution remaining in the tip endof the annular projecting portion of the sealing member 244 is suckedand removed by the plating solution suction mechanism 300, the cylinder314 for horizontal movement is first actuated to advance the platingsolution suction nozzle 302 toward the housing 70, and to introduce theplating solution suction nozzle 302 into the housing 70 through theopening 96 of the housing 70. Thereafter, the cylinder 318 for verticalmovement is actuated to lower the plating solution suction nozzle 302.Thus, the plating solution suction nozzle 302 approaches to and facesthe tip end of the annular projecting portion of the sealing member 244.In this state, while the housing 70 is slowly rotated about a verticalaxis, suction by the vacuum source 310 is performed to remove theplating solution remaining on the half of the entire annular tip end ofthe annular projecting portion of the sealing member 244. Thereafter, inthe reverse operation, the plating solution suction nozzle 302 iswithdrawn from the housing 70. The housing 70 is rotated about thevertical axis by 180 degrees. Thereafter, in the same manner asdescribed above, the plating solution suction nozzle 302 approaches toand faces the tip end of the annular projecting portion of the sealingmember 244. In this state, suction by the vacuum source 310 is performedto remove the plating solution remaining on the remaining half of theannular tip end of the annular projecting portion of the sealing member244.

[0207] Thus, the plating solution left on the tip end of the annularprojecting portion of the sealing member 244 can be sucked and removedin a short time with high efficiency, thus preventing the platingsolution from becoming a source for particles.

[0208] In the plating apparatus according to this embodiment, as withthe third embodiment, when the surface of the plating solution is on alow level for transferring the substrate as shown in FIG. 23, thesubstrate is inserted into and held within the housing 70. In thisstate, the liquid level of the plating solution is raised and thesubstrate is plated. Thereafter, the liquid level of the platingsolution is lowered, and the plated substrate is withdrawn from thehousing 70. After the substrate is withdrawn from the housing 70, ifnecessary, the plating solution remaining on the tip end of the annularprojecting portion of the sealing member 244 is sucked and removed bythe plating solution suction mechanism 300. Further, maintenance iscarried out in such a state that the support 250 and the upper housing264 are raised. In this state, if necessary, a large amount of theplating solution is made to flow and overflows the weir member 58,thereby preventing a crystal of the plating solution from beingdeposited on the inner circumferential surface of the weir member 58.

[0209] Further, in this embodiment, the following process may beperformed: When the surface of the plating solution is on the liquidlevel B for transferring the substrate, the substrate W is inserted intothe housing 70 and held by the housing 70, and then the liquid level ofthe plating solution is raised to the liquid level A for plating. At thesame time, the housing 70 is raised by a certain distance. After theliquid level of the polishing solution reaches the liquid level A forplating, the housing 70 is rotated at a medium speed of, for example,150 min⁻ and lowered, whereby the substrate W is brought into contactwith the surface of the plating solution which rises at its centralportion. Thus, air bubbles on the surface of the substrate can bepositively removed therefrom.

[0210] In the above embodiments, a pre-dipping process is employed inthe pre-treatment unit, and a pre-treatment liquid (a pre-dippingliquid) which is one component of the plating solution is uniformlycoated to improve adhesive property of plating on the surface, to beplated, of the substrate on which a barrier layer and a seed layer aresuccessively provided. Alternatively, a pre-plating method in which apre-plating is applied to reinforce an incomplete seed layer onto thesurface, to be plated, of the substrate on which a barrier layer and aseed layer are successively provided may be used.

[0211] The pre-plating unit using the pre-plating method may havesubstantially the same structure as the plating unit, a weakly alkalineand highly polarized solution of copper pyrophosphate is used as theplating solution, and pure copper (oxygen-free copper) is used as theanode. Instead of the pre-treatment unit 21 employing the pre-dippingmethod shown in FIG. 2, the pre-plating unit having the aboveconstruction may be used, the pre-plating may be carried out toreinforce the incomplete seed layer, and then a process may be shiftedto plating. Further, both of the pre-treatment unit and the pre-platingunit may be provided within the plating apparatus.

[0212] Since the plating solution used in the pre-plating unit isalkaline and the plating solution used in the plating unit is acid, itis necessary not to bring alkali plating solution attached to thesubstrate in the pre-plating unit into the plating unit. Therefore, acleaning device may be provided in the plating section 12 (see FIG. 2)to clean the substrate, which has been subjected to the pre-platingprocess in the pre-plating unit, with water, and the cleaned substratemay be transferred to the plating unit in which plating of the substrateis performed. In the arrangement shown in FIG. 2, at least one of theplating unit (plating units) 22 and the pre-treatment units 21 may bereplaced with a pre-plating unit, and at least one of the pre-treatmentunits 21 may be replaced with the above cleaning device.

[0213] As is apparent from the foregoing description, according to thepresent invention, units (piece of equipment) for continuouslyperforming plating processes and processes incidental to the platingprocess are efficiently disposed in the same system to reduce aninstallation area of the system.

[0214] Further, it is possible to perform a series of treatments,wherein a substrate is taken out from a cassette, is subjected to apre-treatment process and a plating process, and is then rinsed withpure water and dried, in the same system in a continuous and efficientmanner. In addition, the contamination of a substrate with a chemicalused in the plating process or the like can be prevented.

[0215] Although certain preferred embodiments of the present inventionhave been shown and described in detail, it should be understood thatvarious changes and modifications may be made therein without departingfrom the scope of the appended claims.

What is claimed is:
 1. A plating apparatus for continuously plating asurface of a substrate with metal and performing its supplementaryprocess in one housing unit, said plating apparatus comprising: acassette stage for placing a substrate cassette thereon, said substratecassette accommodating a substrate; a pre-treatment unit forpre-treating a surface of a substrate; a plating unit for plating asurface of said substrate pre-treated in said pre-treatment unit; afirst substrate stage disposed between said cassette stage and saidpre-treatment unit for holding a substrate placed thereon; a cleaningand drying unit disposed between said cassette stage and said firstsubstrate stage for cleaning a plated substrate with pure water anddrying said substrate; a first transfer device for transferring asubstrate between said substrate cassette, said cleaning and dryingunit, and said first substrate stage; and a second transfer device fortransferring a substrate between said first substrate stage, saidpre-treatment unit, and said plating unit.
 2. A plating apparatusaccording to claim 1, wherein said first substrate stage comprises twosubstrate stages; and at least one of said two substrate stages in saidfirst substrate stage is constituted so as to place a substrate thereonand clean a substrate.
 3. A plating apparatus according to claim 1,wherein said housing unit has a partition wall for dividing said housingunit into a plating section and a clean section; said plating sectionhas said pre-treatment unit, said plating unit, said fist substratestage, and said second transfer device therein; said clean section hasanother unit therein; said partition wall has a shutter for passing asubstrate therethrough; air can individually be supplied into andexhausted from each of said plating section and said clean section; andthe pressure of said clean section is controlled so as to be higher thanthe pressure of said plating section.
 4. A plating apparatus accordingto claim 1, wherein a container for accommodating a substrate for trialoperation is disposed in said housing unit; and one of said transferdevices takes out said substrate for trial operation from said containerand returns said substrate for trial operation to said container.
 5. Aplating apparatus according to claim 4, wherein said container foraccommodating a substrate for trial operation is disposed in thevicinity of said first substrate stage; and said second transfer devicetakes out said substrate for trial operation from said container andreturns said substrate for trial operation to said container.
 6. Aplating apparatus for continuously plating a surface of a substrate withmetal and performing its supplementary process in one housing unit, saidplating apparatus comprising: a cassette stage for placing a substratecassette thereon, said substrate cassette accommodating a substrate; apre-treatment unit for pre-treating a surface of a substrate; a platingunit for plating a surface of said substrate pre-treated in saidpre-treatment unit; a first substrate stage disposed between saidcassette stage and said pre-treatment unit for holding a substrateplaced thereon; a chemical liquid cleaning unit disposed between saidcassette stage and said first substrate stage for cleaning a platedsubstrate with chemical liquid; a cleaning and drying unit disposedbetween said cassette stage and said chemical liquid cleaning unit forcleaning a plated substrate with pure water and drying said substrate; asecond substrate stage disposed between said chemical liquid cleaningunit and said cleaning and drying unit for holding a substrate placedthereon; a first transfer device for transferring a substrate betweensaid substrate cassette, said cleaning and drying unit, and said secondsubstrate stage; a second transfer device for transferring a substratebetween said first substrate stage, said pre-treatment unit, and saidplating unit; and a third transfer device for transferring a substratebetween said first semiconductor stage, said chemical liquid cleaningunit, and said second substrate stage.
 7. A plating apparatus accordingto claim 6, wherein at least one of said first substrate stage and saidsecond substrate stage comprises two substrate stages; and at least oneof said two substrate stages in said at least one of said firstsubstrate stage and said second substrate stage is constituted so as toplace a substrate thereon and clean a substrate.
 8. A plating apparatusaccording to claim 6, wherein said housing unit has a partition wall fordividing said housing unit into a plating section and a clean section;said plating section has said pre-treatment unit, said plating unit,said fist substrate stage, and said second transfer device therein; saidclean section has another unit therein; said partition wall has ashutter for passing a substrate therethrough; air can individually besupplied into and exhausted from each of said plating section and saidclean section; and the pressure of said clean section is controlled soas to be higher than the pressure of said plating section.
 9. A platingapparatus according to claim 6, wherein a container for accommodating asubstrate for trial operation is disposed in said housing unit; and oneof said transfer devices takes out said substrate for trial operationfrom said container and returns said substrate for trial operation tosaid container.
 10. A plating apparatus according to claim 9, whereinsaid container for accommodating a substrate for trial operation isdisposed in the vicinity of said first substrate stage; and said secondtransfer device takes out said substrate for trial operation from saidcontainer and returns said substrate for trial operation to saidcontainer.
 11. A processing apparatus for processing a semiconductorsubstrate with chemical liquid or pure water, said processing apparatuscomprising: an inverting mechanism for inverting a semiconductorsubstrate.
 12. A plating apparatus for plating a surface of asemiconductor substrate, said plating apparatus comprising: apre-treatment unit for pre-treating a semiconductor substrate to beplated with chemical liquid or pure water, said pre-treatment unithaving an inverting mechanism for inverting said semiconductorsubstrate; and a plating unit for plating a surface of saidsemiconductor substrate pre-treated in said pre-treatment unit.
 13. Aplating method for continuously plating a surface of a substrate withmetal and performing its supplementary process in one housing unit, saidplating method comprising: placing a substrate cassette accommodating asubstrate on a cassette stage; transferring said substrate in saidsubstrate cassette to a first substrate stage by a first transferdevice; transferring said substrate on said first substrate stage to apre-treatment unit from said first substrate stage by a second transferdevice; transferring said substrate pre-treated in said pre-treatmentunit to a plating unit by said second transfer device; and transferringsaid substrate plated in said plating unit to a cleaning and dryingunit.
 14. A plating method for continuously plating a surface of asubstrate with metal and performing its supplementary process in onehousing unit, said plating method comprising: placing a substratecassette accommodating a substrate on a cassette stage; transferring asubstrate in said substrate cassette to a first substrate stage by afirst transfer device; transferring said substrate on said firstsubstrate stage to a pre-treatment unit from said first substrate stageby a second transfer device; transferring said substrate pre-treated insaid pre-treatment unit to a plating unit by said second transferdevice; transferring said substrate plated in said plating unit to saidfirst substrate stage by said second transfer device; transferring saidsubstrate on said first substrate stage to a chemical liquid cleaningunit from said first substrate stage by a third transfer device;transferring said substrate cleaned with chemical liquid in saidchemical liquid cleaning unit to said second substrate stage; andtransferring said substrate on said second substrate stage to a cleaningand drying unit from said second substrate stage.
 15. A plating unithaving a plating process container, said plating process containercomprising: a plating container having a plating chamber therein forholding a plating solution in said plating chamber, said plating chamberhaving an anode at its bottom; a plurality of plating solution supplynozzles for ejecting said plating solution toward the central portion ofsaid plating chamber; a regulating ring provided in the vicinity of theperipheral portion of said plating chamber; a first plating solutiondischarge port for discharging said plating solution in said platingchamber from the bottom of said plating chamber; and a second platingsolution discharge port for discharging said plating solutionoverflowing the peripheral portion of said plating chamber.
 16. Aplating unit according to claim 15, wherein said anode is held by ananode support detachably mounted on said plating container.
 17. Aplating unit comprising: a rotatable housing having a substrate holdingmember provided at the lower end thereof, said substrate holding memberprojecting radially inwardly and abutting a peripheral portion of asubstrate to hold said substrate; and a pressing member disposed in saidhousing for pressing the peripheral portion of said substrate againstsaid substrate holding member to hold said substrate, said pressingmember being rotatable together with said housing.
 18. A plating unitaccording to claim 17, wherein a plurality of air vent holes are formedin said substrate holding member provided at the lower end of saidhousing.
 19. A plating unit according to claim 17, wherein said pressingmember comprises a chuck mechanism disposed at the peripheral portionthereof for detachably holding said substrate on the lower surface ofsaid pressing member.
 20. A plating unit according to claim 17, whereina contact for a cathode electrode is disposed on said substrate holdingmember of said housing; a feeding contact is disposed at the outercircumferential side of said pressing member; said contact for saidcathode electrode is energized when a substrate is held by saidsubstrate holding member and said pressing member; and said feedingcontact energizes said contact for said cathode electrode when saidpressing member is lowered to bring said contact for said cathodeelectrode into contact with said feeding contact.
 21. A plating unitcomprising: a head having a rotatable housing; a vertically movablepressing member housed in said housing; a substrate holding memberdisposed in said housing for holding a peripheral portion of a substratebetween said pressing member ring and said substrate holding member; anda plating process container disposed below said head for holding aplating solution so that the liquid surface of said plating solution hasa liquid level for plating which is higher than a position of asubstrate held by said housing, and a liquid level for transferring thesubstrate which is lower than a position of a substrate held by saidhousing.
 22. A plating unit comprising: a head having a rotatablehousing; a vertically movable pressing ring housed in said housing; asubstrate holding member disposed in said housing for holding aperipheral portion of a substrate between said pressing ring and saidsubstrate holding member; and a plating process container disposed belowsaid head for holding a plating solution so that the liquid surface ofsaid plating solution has a liquid level for plating which is higherthan a position of a substrate held by said housing, and a liquid levelfor transferring the substrate which is lower than a position of asubstrate held by said housing.
 23. A plating unit comprising: a headhaving a rotatable housing; a clamp mechanism with a swing link housedin said housing, said swing link being swingable in the horizontaldirection; a substrate holding member disposed in said housing forholding a peripheral portion of a substrate between said swing link andsaid substrate holding member; and a plating process container disposedbelow said head for holding a plating solution so that the liquidsurface of said plating solution has a liquid level for plating which ishigher than a position of a substrate held by said housing, and a liquidlevel for transferring the substrate which is lower than a position of asubstrate held by said housing.
 24. A plating unit comprising: a headhaving a rotatable housing, said housing having an elastic membertherein elastically deformable by pneumatic pressure; a substrateholding member disposed in said housing for holding a peripheral portionof a substrate between said elastic member and said substrate holdingmember; and a plating process container disposed below said head forholding a plating solution so that the liquid surface of said platingsolution has a liquid level for plating which is higher than a positionof a substrate held by said housing, and a liquid level for transferringthe substrate which is lower than a position of a substrate held by saidhousing.
 25. A plating unit comprising: a head having a rotatablehousing, said housing having a substrate holding member for holding asubstrate; and a plating process container disposed below said head forholding a plating solution so that the liquid surface of said platingsolution has at least two levels.
 26. A plating unit comprising: a headhaving a substrate holding member for holding a substrate; a platingprocess container disposed below said head for holding a platingsolution; and a plating solution suction mechanism for removing aplating solution remaining at a portion abutting on the peripheralportion of a substrate at the inner circumferential end of saidsubstrate holding member.
 27. A plating apparatus for continuouslyplating a surface of a substrate with metal and performing itssupplementary process in one housing unit, said plating apparatuscomprising: a cassette stage for placing a substrate cassette thereon,said substrate cassette accommodating a substrate; a pre-plating unitfor pre-plating a surface of a substrate; a plating unit for plating asurface of said substrate pre-plated in said pre-plating unit; a firstsubstrate stage disposed between said cassette stage and saidpre-plating unit for holding a substrate placed thereon; a cleaning anddrying unit disposed between said cassette stage and said firstsubstrate stage for cleaning a plated substrate with pure water and thendrying said substrate; a first transfer device for transferring asubstrate between said substrate cassette, said cleaning and dryingunit, and said first substrate stage; and a second transfer device fortransferring a substrate between said first substrate stage, saidpre-plating unit, and said plating unit.
 28. A plating apparatus forcontinuously plating a surface of a substrate with metal and performingits supplementary process in one housing unit, said plating apparatuscomprising: a cassette stage for placing a substrate cassette thereon,said substrate cassette accommodating a substrate; a pre-plating unitfor pre-plating a surface of a substrate; a plating unit for plating asurface of said substrate pre-plated in said pre-plating unit; a firstsubstrate stage disposed between said cassette stage and saidpre-plating unit for holding a substrate placed thereon; a chemicalliquid cleaning unit disposed between said cassette stage and said firstsubstrate stage for cleaning a plated substrate with chemical liquid; acleaning and drying unit disposed between said cassette stage and saidchemical liquid cleaning unit for cleaning a plated substrate with purewater and then drying said substrate; a second substrate stage disposedbetween said chemical liquid cleaning unit and said cleaning and dryingunit for holding a substrate placed thereon; a first transfer device fortransferring a substrate between said substrate cassette, said cleaningand drying unit, and said second substrate stage; a second transferdevice for transferring a substrate between said first substrate stage,said pre-plating unit, and said plating unit; and a third transferdevice for transferring a substrate between said first semiconductorstage, said chemical liquid cleaning unit, and said second substratestage.
 29. A plating apparatus for continuously plating a surface of asubstrate with metal and performing its supplementary process in onehousing unit, said plating apparatus comprising: a cassette stage forplacing a substrate cassette thereon, said substrate cassetteaccommodating a substrate; a pre-treatment unit for pre-treating asurface of a substrate; a plating unit for plating a surface of saidsubstrate pre-treated in said pre-treatment unit; a first substratestage for holding a substrate placed thereon; a cleaning and drying unitfor cleaning a plated substrate with pure water and drying saidsubstrate; a first transfer device for transferring a substrate; and asecond transfer device for transferring a substrate; wherein saidhousing unit has a partition wall for dividing said housing unit into aplating section and a clean section; said plating section has at leastsaid pre-treatment unit, said plating unit, said fist substrate stage,and said second transfer device therein; said clean section has anotherunit therein; and the pressure of said clean section is controlled so asto be higher than the pressure of said plating section.
 30. A platingapparatus according to claim 29, wherein said first substrate stagecomprises two substrate stages; and at least one of said two substratestages in said first substrate stage is constituted so as to place asubstrate thereon and clean a substrate.
 31. A plating apparatusaccording to claim 29, wherein a container for accommodating a substratefor trial operation is disposed in said housing unit; and one of saidtransfer devices takes out said substrate for trial operation from saidcontainer and returns said substrate for trial operation to saidcontainer.